Properties of nanoscale magnetically ordered particles of iron oxides and hydroxides, synthesized by different technologies
The characteristics of nanoscale magnetic-ordered particles, synthesized by different technologies, were determined by the methods of electron transmission microscopy, nuclear gamma resonance spectroscopy and magnetometry. The synthesis conditions in used technologies were close to the conditions th...
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| Zitieren: | Properties of nanoscale magnetically ordered particles of iron oxides and hydroxides, synthesized by different technologies / A.P. Shpak, A.B. Brik, N.O. Dudchenko, O.M. Ponomarenko, V.L. Karbovskiy, V.P. Ivanitskiy, O.M. Razumov // Мінералогічний журнал. — 2010. — Т. 32, № 1. — С. 5-13. — Бібліогр.: 21 назв. — англ. |
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Shpak, A.P. Brik, A.B. Dudchenko, N.O. Ponomarenko, O.M. Karbovskiy, V.L. Ivanitskiy, V.P. Razumov, O.M. 2013-09-21T00:31:08Z 2013-09-21T00:31:08Z 2010 Properties of nanoscale magnetically ordered particles of iron oxides and hydroxides, synthesized by different technologies / A.P. Shpak, A.B. Brik, N.O. Dudchenko, O.M. Ponomarenko, V.L. Karbovskiy, V.P. Ivanitskiy, O.M. Razumov // Мінералогічний журнал. — 2010. — Т. 32, № 1. — С. 5-13. — Бібліогр.: 21 назв. — англ. 0204-3548 https://nasplib.isofts.kiev.ua/handle/123456789/49538 537.6 : 543.428.3 : 543.429.3+54.31+577.1 The characteristics of nanoscale magnetic-ordered particles, synthesized by different technologies, were determined by the methods of electron transmission microscopy, nuclear gamma resonance spectroscopy and magnetometry. The synthesis conditions in used technologies were close to the conditions that occur at magnetic biominerals formation in the living organisms. The factors that are most considerably affect the phase composition and magnetic characteristics of synthesized nanoparticles were determined. On the background of the obtained results, the possible means for creation of synthetic analogues of biogenic magnetic-ordered particles, localized in brain tissues, were analyzed. За допомогою методів електронної трансмісійної мікроскопії, ядерної гама-резонансної спек тро скопії та магнітометрії визначені характеристики нанорозмірних магнітовпорядкованих частинок, синтезованих за різними технологіями. У використаних технологіях умови синтезу наближалися до тих умов, які спостерігаються під час формування магнітних біомінералів у живих організмах. Було визначено фактори, що найбільш суттєво впливають на фазовий склад та магнітні характеристики синтезованих наночастинок. На підставі отриманих результатів проаналізовані можливі шляхи створення синтетичних аналогів біогенних магнітовпорядкованих частинок, локалізованих в тканинах мозку. С помощью методов электронной просвечивающей микроскопии, ядерной гамма-резонансной спектроскопии и магнитометрии определены характеристики наноразмерных магнитоупорядоченных частиц, синтезированных по разным технологиям. В использованных технологиях условия синтеза приближались к тем условиям, которые имеют место при формировании магнитных биоминералов в живых организмах. Определены факторы, которые наиболее существенно влияют на фазовый состав и магнитные характеристики синтезированных наночастиц. На основании полученных результатов проанализированы возможные пути создания синтеических аналогов биогенных магнитоупорядоченных частиц, локализованных в тканях мозга. en Інститут геохімії, мінералогії та рудоутворення ім. М.П. Семененка НАН України Мінералогічний журнал Мінералогія Properties of nanoscale magnetically ordered particles of iron oxides and hydroxides, synthesized by different technologies Article published earlier |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine |
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DSpace DC |
| title |
Properties of nanoscale magnetically ordered particles of iron oxides and hydroxides, synthesized by different technologies |
| spellingShingle |
Properties of nanoscale magnetically ordered particles of iron oxides and hydroxides, synthesized by different technologies Shpak, A.P. Brik, A.B. Dudchenko, N.O. Ponomarenko, O.M. Karbovskiy, V.L. Ivanitskiy, V.P. Razumov, O.M. Мінералогія |
| title_short |
Properties of nanoscale magnetically ordered particles of iron oxides and hydroxides, synthesized by different technologies |
| title_full |
Properties of nanoscale magnetically ordered particles of iron oxides and hydroxides, synthesized by different technologies |
| title_fullStr |
Properties of nanoscale magnetically ordered particles of iron oxides and hydroxides, synthesized by different technologies |
| title_full_unstemmed |
Properties of nanoscale magnetically ordered particles of iron oxides and hydroxides, synthesized by different technologies |
| title_sort |
properties of nanoscale magnetically ordered particles of iron oxides and hydroxides, synthesized by different technologies |
| author |
Shpak, A.P. Brik, A.B. Dudchenko, N.O. Ponomarenko, O.M. Karbovskiy, V.L. Ivanitskiy, V.P. Razumov, O.M. |
| author_facet |
Shpak, A.P. Brik, A.B. Dudchenko, N.O. Ponomarenko, O.M. Karbovskiy, V.L. Ivanitskiy, V.P. Razumov, O.M. |
| topic |
Мінералогія |
| topic_facet |
Мінералогія |
| publishDate |
2010 |
| language |
English |
| container_title |
Мінералогічний журнал |
| publisher |
Інститут геохімії, мінералогії та рудоутворення ім. М.П. Семененка НАН України |
| format |
Article |
| description |
The characteristics of nanoscale magnetic-ordered particles, synthesized by different technologies, were determined by the methods of electron transmission microscopy, nuclear gamma resonance spectroscopy and magnetometry. The synthesis conditions in used technologies were close to the conditions that occur at magnetic biominerals formation in the living organisms. The factors that are most considerably affect the phase composition and magnetic characteristics of synthesized nanoparticles were determined. On the background of the obtained results, the possible means for creation of synthetic analogues of biogenic magnetic-ordered particles, localized in brain tissues, were analyzed.
За допомогою методів електронної трансмісійної мікроскопії, ядерної гама-резонансної спек тро скопії та магнітометрії визначені характеристики нанорозмірних магнітовпорядкованих частинок, синтезованих за різними технологіями. У використаних технологіях умови синтезу наближалися до тих умов, які спостерігаються під час формування магнітних біомінералів у живих організмах. Було визначено фактори, що найбільш суттєво впливають на фазовий склад та магнітні характеристики синтезованих наночастинок. На підставі отриманих результатів проаналізовані можливі шляхи створення синтетичних аналогів біогенних магнітовпорядкованих частинок, локалізованих в тканинах мозку.
С помощью методов электронной просвечивающей микроскопии, ядерной гамма-резонансной спектроскопии и магнитометрии определены характеристики наноразмерных магнитоупорядоченных частиц, синтезированных по разным технологиям. В использованных технологиях условия синтеза приближались к тем условиям, которые имеют место при формировании магнитных биоминералов в живых организмах. Определены факторы, которые наиболее существенно влияют на фазовый состав и магнитные характеристики синтезированных наночастиц. На основании полученных результатов проанализированы возможные пути создания синтеических аналогов биогенных магнитоупорядоченных частиц, локализованных в тканях мозга.
|
| issn |
0204-3548 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/49538 |
| citation_txt |
Properties of nanoscale magnetically ordered particles of iron oxides and hydroxides, synthesized by different technologies / A.P. Shpak, A.B. Brik, N.O. Dudchenko, O.M. Ponomarenko, V.L. Karbovskiy, V.P. Ivanitskiy, O.M. Razumov // Мінералогічний журнал. — 2010. — Т. 32, № 1. — С. 5-13. — Бібліогр.: 21 назв. — англ. |
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ISSN 0204-3548. Мінерал. журн. 2010. 32, № 1 5
UDC 537.6 : 543.428.3 : 543.429.3+54.31+577.1
A.P. Shpak, A.B. Brik, N.O. Dudchenko, O.M. Ponomarenko,
V.L. Karbovskiy, V.P. Ivanitskiy, O.M. Razumov
PROPERTIES OF NANOSCALE MAGNETICALLY ORDERED
PARTICLES OF IRON OXIDES AND HYDROXIDES,
SYNTHESIZED BY DIFFERENT TECHNOLOGIES
The characteristics of nanoscale magnetic-ordered particles, synthesized by different technologies, were determined by the
methods of electron transmission microscopy, nuclear gamma resonance spectroscopy and magnetometry. The synthesis
conditions in used technologies were close to the conditions that occur at magnetic biominerals formation in the living
organisms. The factors that are most considerably affect the phase composition and magnetic characteristics of synthesized
nanoparticles were determined. On the background of the obtained results, the possible means for creation of synthetic
analogues of biogenic magnetic-ordered particles, localized in brain tissues, were analyzed.
E-mail: abrik@voliacable.com
МІНЕРАЛОГІЧНИЙ ЖУРНАЛ
MINERALOGICAL JOURNAL
(UKRAINE)
МІНЕРАЛОГІЯ
MINERALOGY
1. Introduction
It is well known that during last years the interest
to nanomineralogy, nanophysics, nanotechnology
and other nanosciences are rapidly grow. It hap-
pens due to the fact, that nanoscale particles have
specific characteristics that are not inherent to the
macroscopic particles [13, 14, 16, 20, 21]. Among
the objects of nanomineralogy, the special interest
is caused by the nanominerals of biogenic origin,
which are formed as a result of vital activity of
biological objects. It is known that physiogenic
biominerals, which formation is programmed by
the Nature at genetic level, are the nanominerals
definitionally [16, 17]. This specified by the fact,
that organic matrix can control the properties
of mineral (inorganic) matter only in the case,
when size of mineral particles are in the range of
nanometers and, accordingly, when the contri-
bution of surface energy to the total energy of
particle is essential [16, 17].
Among the biominerals of different types the most
interesting for us is biomagnetite which is formed in
the organism of humans and other animals [6, 10,
12, 16, 17]. Many scientific works are describing the
research of biomagnetite properties and its role in
the functioning of biological objects. In particular,
it is believed that birds and fish could orientate in
the space by means of biomagnetite [12], and that
biomagnetite plays an important role in the brain
functioning [6, 16, 17]. It is necessary to solve at
least two problems to clarify the mechanisms of
biomagnetite functioning as a navigation device and
as a system of information saving and processing in
brain tissues. First of these problems is associated
with the research of properties of nanomagnetite of
biogenic origin, and second one — with creation of
synthetic analogues of this biominerals.
It is shown in publications [3—7, 16, 17] that
biomagnetite, that is localized in the brain tissues
has a number of unique properties. In particular,
room-temperature macroscopic quantum effects
were registered for this object by means of magnetic
resonance. It is necessary to note, that known at
present time macroscopic quantum effects for
other objects are registered only at extremely low
(Т = 4.2 K) or low (Т = 77 K) temperatures. The
research of properties of biomagnetite, that
demonstrates the occurrence of room-temperature
macroscopic quantum oscilla tions opens up new
possibilities for creation of technical devices for
information saving and processing, which would
use principles of brain functioning, and also for
the study of mechanisms of functioning and
disease of this biological tissue [6, 7, 16, 17]. It is
© A.P. Shpak, A.B. Brik, N.O. Dudchenko,
O.M. Ponomarenko, V.L. Karbovskiy,
V.P. Ivanitskiy, O.M. Razumov, 2010
ISSN 0204-3548. Mineral. Journ. (Ukraine). 2010. 32, No 16
A.P. SHPAK, A.B. BRIK, N.O. DUDCHENKO et al.
important to underline that for the solving of the
applied problems associated with biomagnetite, it
is necessary to develop the technologies related to
creation of synthetic analogues of this biogenic
material. It is shown in the publications [16, 17]
that magnetically ordered nanoparticles localized
in brain tissues for which the term "biomagnetite" is
used, actually are complex multiphase compound
on the basis of different iron oxides and hydroxides.
Many different technologies for creation of
mag netite nanoparticles are described in the
literature, the review of such investigations one
can find in the publications [11, 19]. At the same
time, there are yet many unsolved problems in this
area of knowledge. It is concerned, in particular,
both synthesis technologies and research of the
properties of nanoparticles that have been obtained
by different technologies. The problems concerned
with the creation of multiphase magnetic particles
that could be considered as synthetic analogues of
biomagnetite remain unexplored.
The goals of this work were to investigate the
phase composition, size and the magnetic chara c-
te ristics of magnetically ordered nano particles,
synthesized by different technologies, and to use
the obtained information for the analysis of feasible
technologies for creation of synthetic analogues of
biogenic mag netic nanoparticles localized in the
brain tissues.
2. Studied samples and synthesis technologies
One can assume that the most optimal technologies
for synthetic analogues of biomagnetite creation
are the technologies with the conditions of
nano particles formation, which are maximally
close to the con ditions that are realized during
formation of bio magnetite in the living organism.
The conditions of the magnetite formation, for
example, in bacteria [1], are the following: aqueous
medium in which iron (III) oxyhydroxide initially
appears in membrane vesicle, after that, one-third
of iron (ІІІ) ions are reduce to iron (ІІ) by means
of intracellular reducing agents (for example,
ascorbic acid). It is believed that magnetite is
formed by further dehydration of created substance.
Thus, it was shown that the oxygen concentration
is strongly affecting the process of magnetite bio-
mineralization, namely: the maximal yield of mag-
netite occurs at the concentrations of oxygen about
1 %. Meanwhile, membrane vesicle, that acts part
of restrictor, controls a size and morphology of
magnetite particles and also stabilizes the surface
of nanoparticles. Notably, the basic conditions for
the biogenic magnetic nanoparticles creation are
following: aqueous medium, minimal oxygen
con cen tration, stabilization of particles’ surface.
Tech no logies of synthetic magnetic nano particles
creation, developed in this work, are suffi cient for
the above-listed conditions.
The following materials were used for the
synthesis of nanoparticles: distilled water, con cen-
trated hyd ro chloric acid HCl, solution of am mo-
nia in water NH
4
OH (all — "Chimlaborreactiv"),
iron (ІІ) sulfate heptahydrate FeSO
4
· 7H
2
O,
iron (ІІ) sulfate tetrahydrate FeSO
4
· 4H
2
O,
iron (ІІІ) chloride hexa hydrate FeCl
3
· 6H
2
O,
dextran, chitosan, 25 % glu ta raldehyde solution
OHC(CH
2
)
3
CHO, glacial acetic acid CH
3
CO
2
H,
potassium nitrate KNO
3
, potassium hydroxide
KOH, epichlorhydrin, sodium tetra hyd ridoborate
NaBH
4
(all — Sigma-Aldrich), tetra etho xysilane
(TEOS) SiO
4
(C
2
H
5
)
4
, Fluka, ethanol rectifying.
All solutions were prepared using disti lled water.
In this work the main attention was paid to four
samples that were synthesized by different techno-
logies. The first three samples were synthesized by
the method of hydrothermal precipitation of iron
(II) salt in aqueous medium in the presence of
weak oxidant. All manipulations were performed
in the nitrogen atmosphere. The reagent solutions
(1400 ml of the distilled water, 200 ml of 2.5 M
KOH solution, 200 ml of 1 M KNO
3
solution,
200 ml of 1 M FeSO
4
· 7H
2
O solution) were mixed
quickly in the reaction vessel, the temperature
of the reaction mixture was raised up to 90 °С.
Time of reaction is 2 hours after the necessary
temperature adjustment. After the reaction
comple ting, the created nanoparticles of magnetite
were rinsed by an alkali (0.05 M KOH) using the
magnetic separation method. Immediately after
obtaining of magnetic nanoparticles the 100 ml
of 10 % dextran solution in 1 M KOH were added
to the nanoparticles’ suspension. After 2 hours of
these solutions incubation, 100 mg of NaBH
4
were
added to the mixture, the mixture temperature
was raised up to 50 °C and the incubation under
this temperature was continued during 2 hours.
After that, 2.5 ml of epichlorhydrin were added
drop wise and the mixture was incubated for
more 10 hours at the temperature of 50 °C. Thus,
magnetic nano particles covered by dextran were
obtained (sample 1).
Samples 2 and 3 were obtained as follows. All
manipulations were performed in the nitrogen
atmo sp here. The reagent solutions (1400 ml of
the distilled water, 200 ml of 1.5 M KOH solution,
ISSN 0204-3548. Мінерал. журн. 2010. 32, № 1 7
PROPERTIES OF NANOSCALE MAGNETICALLY ORDERED PARTICLES
200 ml of 2 M KNO
3
solution, 200 ml of 1 M
FeSO
4
· 7H
2
O solution) were mixed quickly in
the reaction vessel, the temperature of the reac-
tion mixture was raised up to 90 °С. Time of reac-
tion is 2 hours after the necessary temperature
adjus tment. After termination of the reaction, the
created nanoparticles of magnetite were washed
by an alkali (0.05 M KOH) using the magnetic
separation method. Immediately after obtaining of
magnetic nanoparticles the 100 ml of 2 % γ-amino-
propyltriethoxysilane solution in 0.05 M KOH
were added to the nanoparticles’ suspension, the
reaction vessel was inserted into the thermostat
and incubated at 90 °C during 2.5 hours at weak
ultrasonic treatment. The reaction vessel was
leaved in the thermostat overnight. After the reac-
tion completing, the created nanoparticles of mag-
ne tite were rinsed by distilled water using the
magnetic separation method. Thus, the sample 2
was obtained.
After that, the part of obtained magnetite nano-
particles was mixed with distilled water in order to
obtain suspension for the next sample synthesis.
For this purpose 14 ml of 0.4 M NaIO
4
solution
were added to 100 ml of 10 % hydroxyethylstarch
solution in water. Mixture was mixed during 2 hours
at a room temperature. The obtained mixture of
the modified starch was added to 100 ml of solu-
tion of modified by γ-aminopropyltriethoxysilane
magne tic nanoparticles; a suspension was treated
ultrasonically and incubated during 4 hours at a
temperature 60 °C. After the reaction completing,
the created nanoparticles of magnetite were rinsed
by distilled water using the magnetic separation
method. Thus, the sample 3 was obtained.
A fourth sample was synthesized by the method
of co-precipitation of Fe2+ and Fe3+ with am-
mo nia in aqueous medium at normal conditions.
Stock solutions of 1 M FeCl
3
· 6H
2
O and 2 M
FeSO
4
· 4H
2
O were prepared as a source of iron
by dissolving the respective chemicals in 2 M
hydrochloric acid under stirring. Stock solution
of 1 M NH
4
OH was prepared by dilution of
concentrated NH
4
OH solution. The reagents
solutions (4 ml of 1 M FeCl
3
· 6H
2
O solution
and 1 ml of a 2 M FeSO
4
· 4H
2
O solution) were
mixed quickly in reaction vessel, and 50 ml of
ammonium solution was added drop-by-drop to
reaction mixture under slow mechanical stirring.
After the reaction completing, magnetic particles
were lightly dispersed using ultrasound dispergator,
rinsed three times with distilled water to remove
the residual surfactant and unreacted reagents.
25 ml of distilled water were added to the obtained
magnetic nanoparticles. After that, 0.1 g of chito-
san in 1 % acetic acid and 8,25 g of urea were
added to the reaction mixture and this mixture was
incubated during 2 hours at 95 °C. After mixture
cooling, the obtained magnetic nanoparticles were
rinsed three times with distilled water to remove the
residual surfactant and unreacted reagents. Thus,
the sample 4 was obtained.
3. Methods of experimental investigations
of the synthesized nanoparticles
The size and morphology of magnetic nano-
par ticles were observed by the method of trans-
mission electron microscopy (TEM) using
PEM-U (Sumy, Ukraine). At investigation using
transmission electronic micro scopy method, the
samples on the thin film are examined with an
accelerated electron beam with the energy of
75 keV. During preparation of the samples for
trans mission electron microscopy the special faci-
lities were used, that allow to avoid aggregation
of nanoparticles. This is very important, because
aggregation of nanoparticles prevents to obtain the
information about the size of nanoparticles and
their size distribution.
The crystal-chemical properties of the state of
iron cations in the structure of magnetite and
coexisting iron-containing phases, their valency,
coordination and distribution on non-equivalent
positions, and also the internal magnetic fields
on their nuclei were studied by the method of
nuclear gamma-resonance spectroscopy (NGR-
spectroscopy). NGR-spectra were obtained on the
"Wissel" spectrometer (FRG); the source of the
emission was 57Со in the matrix of Cr. The spectra
processing was carried out with the use of the
program which realizes a least-squares method.
Magnetic researches were performed by means
of magnetometer with Hall sensor (Kyiv, Ukraine),
that is intended for the measuring of hysteresis
loop parameters of powder-like isotropic and
aniso tropic materials by maximum and partial
hysteresis cycles. In this device, the measurement
of parameters of magnetization curves and hysteresis
loops are taking place in the open magnetic circuit.
Cylinder-shaped observable sample is introduced
to the interpolar space of electromagnet. The
differential pair of Hall sensors with the magnetic
axes oriented parallel to the vector of electromagnet
external magnetic field is located in immediate
proximity to the sample. The measuring sensors
with such orientation don’t respond to the external
ISSN 0204-3548. Mineral. Journ. (Ukraine). 2010. 32, No 18
A.P. SHPAK, A.B. BRIK, N.O. DUDCHENKO et al.
field, and the origin of measured signal is related
only to the sample field component, that is in
direct proportion to value of its magnetic moment.
The calibration with the use of standard speci-
men with known saturation magnetization was
carrying out for determination of absolute value of
magnetic moment (magnetization) of observable
samples. The nickel was used as a standard
specimen, the saturation magnetization of which
is determined with high accuracy (54.4 A · m2/kg
at a room temperature).
4. Experimental results and discussion
4.1. Transmission electron microscopy. Electron
micro graphs of synthesized nanoparticles obtained
by the method of hydrothermal precipitation of
iron (II) salt in aqueous medium in the presence
of weak oxidant (a — sample 1) and by the method
of co-precipitation (b — sample 4) are shown on
the Fig. 1. The presented microphotographs are
show that magnetic nanoparticles obtained by the
method of hydrothermal precipitation of iron (II)
salt in aqueous medium in the presence of weak
oxidant have cubic shape and the mean size of the
magnetite core is 30 nm. Magnetic nanoparticles,
obtained by the co-precipitation method are
elongated and the mean size of the magnetite core
of these particles is approximately 100 nm (the
mean sizes of magnetite cores of all synthesized
nanoparticles are shown in the Table 1). Thus, on
the basis of the obtained results one can conclude,
that synthesis of nanoparticles by the method of
the hydrothermal precipitation, that is conducted
in the oxygen-free atmosphere and at the increased
temperature, allows to obtain the cubic-shaped
nanoparticles of less size, and synthesis of nano-
particles by the method of co-precipitation, that
conducted in oxygen atmosphere and at room tem-
perature results in formation of elongated particles
of greater size.
4.2. Nuclear gamma-resonance (NGR) spectro-
scopy. The NGR-spectra of investigated samples
are shown at the Fig. 2, the parameters of these
spectra are shown in the Table 2. Spectrum of
sample 1 is presented by two sextets of magnetic
splitting (Fig. 2, a). On the basis of comparison
of sextets parameters with literature data [2, 15],
the spectrum of sample 1 was related to resonance
absorption in magnetite. Thus, the sextet with
the greater value of H
eff
was related to resonance
contribution of Fe3+ ions in tetrahedral (А) posi-
tions of magnetite structure, and the sextet with
smaller H
eff
was related to total contribution of
Fe3+ and Fe2+ ions in octahedral (В) positions.
Inseparability of Fe3+ and Fe2+ contributions in
octahedral sub-lattice is explained by an electronic
exchange between them. On the assumption of struc-
tural data about quantitative correlation of positions
A and B in the unit cell of magnetite (8 : 16), the
ratio of lines areas of series A and B (SA / SB) for
magnetite of stoichiometrical composition is 0.5.
Deviation of SA / SB ratio from this value is related
with occurrence of isomorphic substitutions in
a structure, with oxidization of Fe2+ or with the
presence of non-identified admixture phases with
the parameters, that are close to the sextets A and B.
Experimentally found value SA / SB for a sample 1
is 0.859 that is the evidence of considerable
oxidization of octahedral Fe2+ cations.
Spectra of samples 2 and 3 (Fig. 2, b, c) are
presented by superposition of three sextets of
Fig. 1. Electron of micrographs of synthesized nanoparticles: a — sample 1; b — sample 4.
Sample Coverage
Particles
size, nm
Saturation
magnetization,
A·m2/kg
Mr / Ms
1 Dextran 30 83 0
2 γ-AРS 25 — —
3 Hydroxyethylstarch 25 73 0
4 Chitosan 100 30 0.17
Table 1. Descriptions of the synthesized
magnetic nanoparticles
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PROPERTIES OF NANOSCALE MAGNETICALLY ORDERED PARTICLES
mag netic splitting, two of which, with the greater
values of the magnetic splitting, were referred to
magnetite by the parameters values. The value of
ratio SA / SB in a spectrum of the sample 2 is 0.992
that is the evidence of increasing of iron oxidation
degree in its structure in comparison with sample 1.
Fig. 2. NGR-spectra of synthesized samples: a—d — samples 1—4 correspondingly.
Table 2. Parameters of NGR-spectra of the synthesized samples
Sample Iron position Н
eff
, kOe
I. S. Q. S. G
S, % (SA
/SB)
mm/s
1
Magnetite
А-position 491 0.29 0.01 0.35—0.39 46.2
0.859
В-position 458 0.65 0.00 0.35—0.57 53.8
2
Magnetite
А-position 490 0.29 0.02 0.36—0.41 46.9
0.992В-position 459 0.67 0.01 0.35—0.61 47.3
Goethite
376 0.35 0.25 0.31—0.57 5.8 —
3
Magnetite
А-position 490 0.29 0.01 0.35—0.41 42.6
0.816В-position 457 0.65 0.01 0.37—0.58 52.2
Goethite
376 0.35 0.27 0.37—0.42 5.2 —
4
Maghemite
1 483 0.32 0.00 0.39—0.50 29.5
—2 460 0.33 0.03 0.45—0.62 23.3
3 428 0.35 0.03 0.63—0.86 25.8
Goethite
1 388 0.37 0.10 1.11—2.45 24.1 —
N o t e. Н
eff
— effective magnetic field on the iron nucleus; I.S. — an isomer shift relative to the α-iron; Q.S. — quadrupole
splitting; G — absorption line half-width; S — relative area of the component. Measurement error: Н
eff
— ±5 kOe, I. S.,
Q. S., G — ±0.03 mm/s, S — ±5 %.
10 ISSN 0204-3548. Mineral. Journ. (Ukraine). 2010. 32, No 1
A.P. SHPAK, A.B. BRIK, N.O. DUDCHENKO et al.
Third sextet with the minimum value of splitting
was related to goethite (α-FeOOH) according to
the comparison of its parameters with literature data
[18]. The resonance contributions of goethite to
the spectra of samples 2 and 3 are 5.8 % and 5.2 %,
correspondingly. The oxidation degree of structural
iron in magnetite of the sample 3 is minimum
(SA / SB = 0.816) in comparison with two mentioned
above samples.
NGR-spectrum of sample 4 is characterized by
significant decrease of resonance absorption and
broadening of the spectra lines. The last is the evi-
dence of complex superposition of several resonance
sextets in the aggregate spectrum. Spectrum of
sample 4 was approximated by four sextets of the
magnetic splitting (Fig. 2, d). Three sextets with
the high values of Н
eff
(483, 460 and 428 kOe) and
total contribution of 78.6 % were referred to the
resonance absorption of gamma-quants by the
nuclei of Fe3+ ions in the structure of maghemite
(γ-Fe
2
O
3
) [18] according to the spectroscopic para-
meters. The sextet with the minimum value of Н
eff
(388 kOe), with maximal value of the quadrupole
splitting and total contribution of 21.4 % was
referred to the resonance absorption of Fe3+ in the
goethite structure. The presence in the spectrum of
three components of maghemite could be related
with the characteristic properties of the structure of
surface layers of nanodispersed particles and their
inhomogeneity.
Considerable broadening of resonance lines of
goethite one could explain by the watering of its’
structure and formation of hydrogoethite which
meets the formula α-FeOOH · nH
2
O, where n could
be in a range from 0 to 0.5. In is necessary to note,
that hydrogoethite have antiferromagnetic and weak
ferrimagnetic properties. Water and the products of
its dehydration could affect the weak ferrimagnetic
properties only in the case of formation non-homo-
geneities in the crystal lattice that are disturbing
the collinearity of Fe3+ spins. The water in the
structure of goethite and structure defects of both
iron-con taining phases, probably, causes the de-
creasing of resonance absorption in the spectrum
of sample 4.
On the background of the obtained results it is
possible to conclude, that synthesis of nanoparticles
by the method of the hydrothermal precipitation,
that is conducted in the oxygen-free atmosphere
allows to obtain magnetite nanoparticles with the
small admixtures of goethite (that is formed due
to the oxidization of magnetite by oxygen, that was
not completely removed from the reaction mix-
ture), and synthesis by the method of co-pre-
cipitation, that was conducted in the oxygen
atmosphere and at a room temperature resulted in
Fig. 3. Magnetization curves for the samples 1 (a), 3 (b),
4 (c).
11ISSN 0204-3548. Мінерал. журн. 2010. 32, № 1
PROPERTIES OF NANOSCALE MAGNETICALLY ORDERED PARTICLES
formation of mag hemite particles with the ad-
mixtures of goethite.
4.3. Magnetic properties. Magnetic characte-
ris tics were experimentally investigated for the
samples 1, 3 and 4. Obtained results are shown at
the Fig. 3, where the hysteresis curves are figured
for the observable samples, and also in the Table 1.
It is known, that hysteresis curves are characterized
by saturation magnetization (Ms), saturation
remanence (Mr) and coercivity (Hc). Analysis of
these values, and also the Mr /Ms ratio enables
one to make a conclusion about the peculiarities
of the magnetic state of observable samples. It is
known, that magnetic characteristics of magnetite
are determined by its structure. Magnetite has
ferrimagnetic properties, as magnetic moments of
octahedrically coordinated ions Fe2+ and Fe3+
are parallel to each other and antiparallel to the
magnetic moment of Fe3+ ions, that located in the
vertexes of tetrahedrons. The hysteresis curves of
magnetite nanoparticles are essentially depend on
the domain state of these particles [8, 9, 12]. The
individual magnetic particles could be subdivided
into superparamagnetic, single domain, pseudo-
single domain (the presence of coupled single
domain states) and multidomain states. By means of
the experimentally registered hysteresis curves and
its characteristics it is possible to make conclusions
about the magnetic state of nanoparticles [9].
From the experimental dependencies, presented
on the Fig. 3, it is possible to see that the satura-
tion magnetization could be determined accura-
te ly for observable samples and these values are
unequal for different samples (Table 1). The dif-
fe rent values of saturation magnetization for sam-
p les 1 and 3 are conditioned, probably, by the
different degree of these samples’ imperfection and
by the presence in the sample 3 of goethite phase.
The essential decrease of the Ms value for a sample 4
is conditioned, probably, mainly by the fact, that
the structure of this sample is represented by the
maghemite with the high degree of crystal lattice
disordering, and also by the presence of goethite
phase in this sample. The Mr value could reliably
be determined only for a sample 4 (Table 1). The
Mr value for a sample 1 is equal to zero, and this
value for a sample 3 is very small, that obstructs its
measuring. Coercivity Hc for samples 1 and 3 are
equal to zero. This value for the sample 4 is not
equal to zero, but is very small, that obstructs the
experimental determination of its value.
The determination of Mr /Ms ratio is an im por-
tant test in the differentiation between single- and
multidomain particles. In our case, the shapes of
the hysteresis curves of samples 1 and 3 are extre-
mely thin, i. e. Mr /Ms ≈ 0 that is the characteristic
property of superparamagnetic nanoparticles. Super -
para mag netic nanoparticles demonstrating very
rapid initial increasing of magnetization with the
field increasing, then the gradual increasing of
magnetization up to saturation is take place. In
addition, superparamagnetic particles do not reveal
the saturation remanence and coercivity. These
characters are present for the hysteresis curves,
registered for samples 1 and 3.
The ratio Mr /Ms for sample 4 is approximately
0.17. According to the publication [9], the hyste-
resis curves for pseudo-single domain par t icles are
characterized by the Mr /Ms values in a range of
0.1—0.5. That is why, it is possible to assume, that
nanoparticles of sample 4 are pseudo-single
domain. This conclusion is confirmed by the
data about the size of sample 4 particles, that was
obtained by the method of electron microscopy
(100 nm), and also by the data about the com-
position and structure of these particles, determi-
ned by NGR-spectroscopy.
Thus, on the basis of Mr /Ms ratio values,
size of magnetic nanoparticles and their phase
composition one could make a conclusion about
the domain state of the synthesized magnetic
nanoparticles. The particles of samples 1 and
3, that were synthesized by the hydrothermal
precipitation of iron (II) salt in aqueous medium
in the presence of weak oxidant, that have sizes of
25—30 nm and that consist mainly of magnetite
are superparamagnetic. Particles of sample 4 that
synthesized by the method of co-precipitation, that
have sizes of 100 nm and that consist of maghemite
and goethite mixture are pseudo-single domain.
5. Conclusion
The obtained experimental results are allowing
to analyze the influence of synthesis conditions
on the size, phase composition and magnetic
properties of synthesized nanoparticles, obtained
by different technologies. Comparison of the des-
cribed above characteristics of synthesized par ticles
with respective characteristics of biogenic magnetic
nanoparticles can be the basis for the solving of
the problem, associated with development of
crea tion technologies of synthetic analogues of
magnetic-ordered particles, localized in the brain
tissues. For the decision of these problems, the
processes of nanoparticles’ formation, which are
described above in this work, must be held in the
12 ISSN 0204-3548. Mineral. Journ. (Ukraine). 2010. 32, No 1
A.P. SHPAK, A.B. BRIK, N.O. DUDCHENKO et al.
presence of organic matrix, that is jointly with
magnetic-ordered nanoparticles need to form the
hybrid organic-mineral nanosystem. The above
mentioned information about the dependence of
phase composition and magnetic characteristics
of nanoparticles from the peculiarities of synthesis
technologies could be used to choose the optimal
conditions of creation of the synthetic analogues of
biominerals. On the background of described above
properties of synthetic nanoparticles as well as the
properties of biogenic magnetic biominerals, it is
possible to assume, that optimal technologies of
creation of considered synthetic organic-mineral
materials must include the formation of iron
hydroxide nanoparticles associated with organic
matrix, and then, the transformation of these
hydroxides into iron oxides. Such transformation
could be held due to the processes of dehydration
and dexydroxylation, as well as due to the additional
oxidation or reduction of iron ions. The criterion
of equivalence of the synthetic hybrid organic-
mineral nanosystems to the biogenic magnetic
nanosystems localized in brain tissues must be
the presence at synthetic materials of the above
mentioned coherent effects that are demonstrated
by the magnetic nanoparticles of biogenic origin.
In conclusion, the following should be mentioned,
the creation of synthetic organic-mineral nano-
ma terials, that demonstrating the unique charac-
teristics of biogenic magnetite, opens up the new
possibilities for many fundamental and applied
problems’ solving.
1. Basylinsky D.A., Frankel R.B. Biologically controlled mineralization in prokaryotes // Revs Miner. and Geochem. —
2003. — 54, No 1. — P. 217—247.
2. Bauminger R., Cohen S. G., Marinov A. et. al. Study of the low-temperature transition in magnetite and the internal
fields acting on iron nuclei in some spinal ferrites, using Mossbauer absorption // Phys. Rev. — 1961. — 123, No 5. —
P. 1447—1450.
3. Brik A.B. Anomalous signals registered by EPR spectrometer in nano-scale particles of organic and mineral components
of biominerals // Mineral. Journ. (Ukraine). — 2002. — 24, No 5/6. — P. 29—39.
4. Brik A.B. Angular dependencies of anomalous signals registered by EPR spectrometer in mineralized biological
tissues // Ibid. — 2003. — 25, No 2/3. — P. 11—21.
5. Brik A.B. Nanoscale inorganic particles localized in biological tissues // STCU : Intern. RD Partnership. — 2005. —
P. 27.
6. Brik A.B., Shpak A.P., Rozenfeld L.G. et al. Properties of magnetically ordered mineral inclusions, localized in the
brain tissues // Materials of the Forth Intern. Miner. Sem. "Theory, history, philosophy and practice of mineralogy". —
Syktyvkar, 2006. — P. 24—25 (in Russian).
7. Brik A., Shpak A., Rozenfeld L. et al. Anomalous properties of biomagnetics localized in brain tissue and synthetic
analogues of the biohybrid systems // Abstr. of Ukr.-Germ. Symp. on Nanobiotechnology. — Kiev, 2006. — P. 35.
8. Davila A.F. Detection and function of biogenic magnetite : Ph.D. Thesis. — Munchen, 2005.
9. Hitchhiker’s Guide to Magnetism. Bruce M. Moskowitz //http://www.magneticmicrosphere.com/resources/
hitchhikers_guide.php
10. Kirschvink J.L., Kobayashi-Kisrchvink A., Woodford B.J. Magnetite biomineralization in the human brain // Proc. Nat.
Acad. Sci. USA. — 1992. — 89. — P. 7683—7687.
11. Laurent S., Forge D., Port M. et. al. Magnetic iron oxide nanoparticles : synthesis, stabilization, vectorization,
physicochemical characterizations, and biological applications // Chem. Rev. — 2008. — 108, No 6. — P. 2064—2110.
12. Magnetite biomineralization and magnetoreception in organisms. A new biomagnetism / Eds. J.L. Kirschvink,
D.S. Jones, B.J. MacFadden. — New York; London : Plenum Press, 1985. — 907 р.
13. Mineralogical intervention into micro- and nanoworld // Materials of the Intern. Miner. Sem. / Eds. A.M. Askhabov,
N.P. Yushkin. — Syktyvkar : Geoprint, 2009. — 548 p. (in Russian).
14. Pavlyshyn V.I., Matkovskyy O.I., Dovgyy S.O. Genesis of minerals. — Kiev : VPC "Kyiv. univ.", 2003. — 672 p. (in
Ukrainian).
15. Romanov V.P., Checherskyy V.D. Influence of nonstoichiometry on the Mossbauer spectra of magnetite // Fizika tverdogo
tela. — 1970. — 12, No 6. — P. 1853—1855 (in Russian).
16. Shpak A.P., Brik A.B., Karbovskiy V.L., Rozenfeld L.G. Properties of nanoscale particles on the basis of metals localized
into biological tissues // Progress in Physics of Metals. — 2003. — 4, No 4. — P. 303—336.
17. Shpak A.P., Rozenfeld L.G., Brik А.B. et al. Magnetic resonance of magnetically ordered particles in the brain tissue //
Physiol. Journ. — 2005. — 51, No 5. — P. 16—22 (in Ukrainian).
18. Takada T., Kiyama M., Bando Y. et. al. Mossbauer study of α-, β- and γ-FeOOH // J. Phys. Soc. Japan. — 1964. — 19,
No 9. — P. 1774—1779.
19. Tartaj P., Morales M.P., Veintemillas-Verdaguer S. et al. Synthesis, properties and biomedical applications of magnetic
nanoparticles. Handbook of Magnetic Materials. — Amsterdam : Elsevier, 2006. — 403 р.
13ISSN 0204-3548. Мінерал. журн. 2010. 32, № 1
PROPERTIES OF NANOSCALE MAGNETICALLY ORDERED PARTICLES
20. Yushkin N.P., Askhabov A.M., Magomedov M.N. et al. Nanomineralogy. Ultra- and microdisperse states of mineral
matter. — SPb. : Nauka, 2005. — 581 p. (in Russian).
21. Yushkin N.P., Pavlyshyn V.I., Askhabov A.M. Ultradisperse state of mineral matter and problems of nanomineralogy //
Mineral. Journ. (Ukraine). — 2003. — 25, Nо 4. — P. 7—31 (in Russian).
G.V. Kurdumov Inst. of Metallophysics of the NAS of Ukraine, Kyiv Received 24.12.2009
M.P. Semenenko Inst. of Geochemistry, Mineralogy and Ore
Formation of the NAS of Ukraine, Kyiv
РЕЗЮМЕ. За допомогою методів електронної трансмісійної мікроскопії, ядерної гама-резонансної спек тро скопії
та магнітометрії визначені характеристики нанорозмірних магнітовпорядкованих частинок, синтезованих за різ-
ними технологіями. У використаних технологіях умови синтезу наближалися до тих умов, які спостерігаються під
час формування магнітних біомінералів у живих організмах. Було визначено фактори, що найбільш суттєво впли-
вають на фазовий склад та магнітні характеристики синтезованих наночастинок. На підставі отриманих резуль-
татів проаналізовані можливі шляхи створення синтетичних аналогів біогенних магнітовпорядкованих частинок,
локалізованих в тканинах мозку.
РЕЗЮМЕ. С помощью методов электронной просвечивающей микроскопии, ядерной гамма-резонансной спек-
тро скопии и магнитометрии определены характеристики наноразмерных магнитоупорядоченных частиц, син-
те зированных по разным технологиям. В использованных технологиях условия синтеза приближались к тем ус-
ловиям, которые имеют место при формировании магнитных биоминералов в живых организмах. Определены
факторы, которые наиболее существенно влияют на фазовый состав и магнитные характеристики синтезирован-
ных наночастиц. На основании полученных результатов проанализированы возможные пути создания синте-
ических аналогов биогенных магнитоупорядоченных частиц, локализованных в тканях мозга.
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