Negative magnetoresistance in indium antimonide whiskers doped with tin
Negative magnetoresistance of InSb whiskers with different impurity concentrations 4.4 × 10 ¹⁶–7.16 × 10 ¹⁷ cm −³ was studied in longitudinal magnetic field 0–14 T in the temperature range 4.2–77 K. The negative magnetoresistance reaches about 50% for InSb whiskers with impurity concentration in the...
Saved in:
| Published in: | Физика низких температур |
|---|---|
| Date: | 2016 |
| Main Authors: | , , , |
| Format: | Article |
| Language: | English |
| Published: |
Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
2016
|
| Subjects: | |
| Online Access: | https://nasplib.isofts.kiev.ua/handle/123456789/129135 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Journal Title: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Cite this: | Negative magnetoresistance in indium antimonide whiskers doped with tin / A. Druzhinin, I. Ostrovskii, Yu. Khoverko, N. Liakh-Kaguy // Физика низких температур. — 2016. — Т. 42, № 6. — С. 581-585. — Бібліогр.: 25 назв. — англ. |
Institution
Digital Library of Periodicals of National Academy of Sciences of Ukraine| id |
nasplib_isofts_kiev_ua-123456789-129135 |
|---|---|
| record_format |
dspace |
| spelling |
Druzhinin, A. Ostrovskii, I. Khoverko, Yu. Liakh-Kaguy, N. 2018-01-16T15:28:18Z 2018-01-16T15:28:18Z 2016 Negative magnetoresistance in indium antimonide whiskers doped with tin / A. Druzhinin, I. Ostrovskii, Yu. Khoverko, N. Liakh-Kaguy // Физика низких температур. — 2016. — Т. 42, № 6. — С. 581-585. — Бібліогр.: 25 назв. — англ. 0132-6414 PACS: 76.60.–k, 72.15.Rn, 73.43.Qt https://nasplib.isofts.kiev.ua/handle/123456789/129135 Negative magnetoresistance of InSb whiskers with different impurity concentrations 4.4 × 10 ¹⁶–7.16 × 10 ¹⁷ cm −³ was studied in longitudinal magnetic field 0–14 T in the temperature range 4.2–77 K. The negative magnetoresistance reaches about 50% for InSb whiskers with impurity concentration in the vicinity to the metal–insulator transition. The negative magnetoresistance decreases to 35 and 25% for crystals with Sn concentration from the metal and dielectric side of the transition. The longitudinal magnetoresistance twice crosses the axis of the magnetic field induction for the lightly doped crystals. The behavior of the negative magnetoresistance could be explained by the existence of classical size effect, in particular boundary scattering in the subsurface whisker layer. en Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України Физика низких температур Низкотемпеpатуpный магнетизм Negative magnetoresistance in indium antimonide whiskers doped with tin Article published earlier |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| title |
Negative magnetoresistance in indium antimonide whiskers doped with tin |
| spellingShingle |
Negative magnetoresistance in indium antimonide whiskers doped with tin Druzhinin, A. Ostrovskii, I. Khoverko, Yu. Liakh-Kaguy, N. Низкотемпеpатуpный магнетизм |
| title_short |
Negative magnetoresistance in indium antimonide whiskers doped with tin |
| title_full |
Negative magnetoresistance in indium antimonide whiskers doped with tin |
| title_fullStr |
Negative magnetoresistance in indium antimonide whiskers doped with tin |
| title_full_unstemmed |
Negative magnetoresistance in indium antimonide whiskers doped with tin |
| title_sort |
negative magnetoresistance in indium antimonide whiskers doped with tin |
| author |
Druzhinin, A. Ostrovskii, I. Khoverko, Yu. Liakh-Kaguy, N. |
| author_facet |
Druzhinin, A. Ostrovskii, I. Khoverko, Yu. Liakh-Kaguy, N. |
| topic |
Низкотемпеpатуpный магнетизм |
| topic_facet |
Низкотемпеpатуpный магнетизм |
| publishDate |
2016 |
| language |
English |
| container_title |
Физика низких температур |
| publisher |
Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України |
| format |
Article |
| description |
Negative magnetoresistance of InSb whiskers with different impurity concentrations 4.4 × 10 ¹⁶–7.16 × 10 ¹⁷ cm −³ was studied in longitudinal magnetic field 0–14 T in the temperature range 4.2–77 K. The negative magnetoresistance reaches about 50% for InSb whiskers with impurity concentration in the vicinity to the metal–insulator transition. The negative magnetoresistance decreases to 35 and 25% for crystals with Sn concentration from the metal and dielectric side of the transition. The longitudinal magnetoresistance twice crosses the axis of the magnetic field induction for the lightly doped crystals. The behavior of the negative magnetoresistance could be explained by the existence of classical size effect, in particular boundary scattering in the subsurface whisker layer.
|
| issn |
0132-6414 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/129135 |
| citation_txt |
Negative magnetoresistance in indium antimonide whiskers doped with tin / A. Druzhinin, I. Ostrovskii, Yu. Khoverko, N. Liakh-Kaguy // Физика низких температур. — 2016. — Т. 42, № 6. — С. 581-585. — Бібліогр.: 25 назв. — англ. |
| work_keys_str_mv |
AT druzhinina negativemagnetoresistanceinindiumantimonidewhiskersdopedwithtin AT ostrovskiii negativemagnetoresistanceinindiumantimonidewhiskersdopedwithtin AT khoverkoyu negativemagnetoresistanceinindiumantimonidewhiskersdopedwithtin AT liakhkaguyn negativemagnetoresistanceinindiumantimonidewhiskersdopedwithtin |
| first_indexed |
2025-11-26T01:42:50Z |
| last_indexed |
2025-11-26T01:42:50Z |
| _version_ |
1850605390448820224 |
| fulltext |
Low Temperature Physics/Fizika Nizkikh Temperatur, 2016, v. 42, No. 6, pp. 581–585
Negative magnetoresistance in indium antimonide
whiskers doped with tin
A. Druzhinin1,2, I. Ostrovskii1,2, Yu. Khoverko1,2, and N. Liakh-Kaguy1
1Lviv Polytechnic National University, 12 S. Bandera Str., Lviv 79013, Ukraine
E-mail: druzh@polynet.lviv.ua
2International Laboratory of High Magnetic Fields and Low Temperatures, Gajowicka 95, Wroclaw, Poland
Received November 27, 2015, revised February 9, 2016, published online April 25, 2016
Negative magnetoresistance of InSb whiskers with different impurity concentrations 4.4⋅1016 –7.16⋅1017 сm–3
was studied in longitudinal magnetic field 0–14 T in the temperature range 4.2–77 K. The negative magneto-
resistance reaches about 50% for InSb whiskers with impurity concentration in the vicinity to the metal–insulator
transition. The negative magnetoresistance decreases to 35 and 25% for crystals with Sn concentration from the
metal and dielectric side of the transition. The longitudinal magnetoresistance twice crosses the axis of the mag-
netic field induction for the lightly doped crystals. The behavior of the negative magnetoresistance could be ex-
plained by the existence of classical size effect, in particular boundary scattering in the subsurface whisker layer.
PACS: 76.60.–k Nuclear magnetic resonance and relaxation;
72.15.Rn Localization effects (Anderson or weak localization);
73.43.Qt Magnetoresistance.
Keywords: negative magnetoresistance, InSb whiskers, transverse and longitudinal magnetoresistance, metal–insulator
transition.
Introduction
Negative magnetoresistance (NMR) was observed in
InSb crystals at low temperatures and weak magnetic fields
[1–9]. There are various interpretations of this effect due to
different mechanisms of scattering of charge carriers. In
particular: 1) surface boundary scattering [1,2]; 2) scatter-
ing on magnetic impurities [3–5]; 3) scattering on non-
magnetic impurities with concentration in the vicinity to
metal–insulator transition (MIT) [5–9].
Negative magnetoresistance was found in InSb films
[1,2]. Transverse and longitudinal magnetoresistance in
InSb thin films grown on GaAs substrates were studied at
temperatures 4.2, 80 and 300 K [1]. NMR of undoped InSb
film was observed only in magnetic fields parallel to the
film at high temperatures. The negative magnetoresistance
effect is connected with surface boundary scattering in the
plane normal to InSb film. Positive magnetoresistance
shows the logarithmic increase with anisotropy between
parallel and perpendicular orientation of magnetic field.
It’s arising from the two-dimensional weak anti-loca-
lization that reflects strong spin–orbit interaction caused by
the asymmetric potential at the interface. At low tempera-
tures (about 80 K), the transport is dominated by the two-
dimensional electrons in the accumulation layers at the
InSb/GaAs heterointerface [1].
In Sn-doped InSb films, the negative magnetoresistance
was found in extremely weak magnetic fields [2]. Its ap-
pearance was observed before the Shubnikov–de Haas os-
cillations. The negative magnetoresistance crossovers to
the positive magnetoresistance occurs with the decrease of
the film thickness to 0.1 mm. These effects were analyzed
and the spin–orbit scattering rate in the intrinsic InSb film
due to the bulk inversion asymmetry has been found. The
crossover from weak localization to weak anti-localization
with decreasing InSb film thickness from 1 to 0.1 mm was
found for Sn-doped films in weak magnetic fields before
the appearance of the Shubnikov–de Haas oscillations [2].
Magnetic and transport properties of indium antimonide
doped with manganese were studied in the temperature
range 1.6–300 K and magnetic fields up to 15 T [3,4].
Negative magnetoresistance was revealed in diluted mag-
netic semiconductor InSb:Mn with nanosize MnSb precipi-
tates [4]. The positive magnetoresistance was observed at
temperatures above 10 K [4]. It transforms into negative
magnetoresistance with the decrease of the temperature.
© A. Druzhinin, I. Ostrovskii, Yu. Khoverko, and N. Liakh-Kaguy, 2016
A. Druzhinin, I. Ostrovskii, Yu. Khoverko, and N. Liakh-Kaguy
The temperature dependence of negative magnetoresistance
was explained by damping of the spin-dependent scattering
of charge carriers in magnetic field.
Magnetoresistance of nonmagnetic InSb single crystal
doped with manganese with impurity concentration
1.5⋅1017 cm−3 was investigated in the temperature range
40 mK–300 K and magnetic fields 0–25 T [5–8]. Colossal
decrease of resistivity in p-type InSb(Mn) crystals was
revealed in magnetic fields 0–4 T at superlow tempera-
tures [5]. The Hall constant changes its sign under varia-
ble temperature and magnetic field.
The behavior of magnetic Mn- and nonmagnetic Ge-
impurities was compared in InSb. Ge like Mn forms shallow
acceptor level and demonstrates exactly the same critical con-
centration of metal–insulator transition at Ncr = 2⋅1017 cm−3.
The magnetotransport characteristics of p-InSb(Ge) crys-
tals at low temperatures differ from p-InSb(Mn) character-
istics [6]. InSb crystals doped by Ge do not demonstrate
resistivity dependense on impurity concentration, temperature
and magnetic field, but it demonstrates the variable range
hopping conductivity, and positive magneotresistance typical
for disordered localized nonmagnetic impurities.
The resistivity near the metal–insulator transition in
InSb:Mn and InSb:Ge were studied and negative magneto-
resistance was observed at temperature 1.6 K [9]. InSb:Mn
exhibits a strong enhancement of the resistivity below 10 K.
Negative magnetoresistance effect increases by applying
hydrostatic pressure. The exchange interaction between the
hole spin of the Mn acceptor is the dominant correlation effect
leading to the formation of an antiferromagnetic alignment of
the Mn spins along the percolation path which inhibits hop-
ping of holes between neighboring Mn sites.
Our previous magnetoresistance studies of InSb whiskers
doped with Sn [10,11] revealed negative magnetoresistance at
low temperatures in weak magnetic fields, but its behavior
wasn’t analyzed at different temperatures and doping levels. It
is interesting to consider transport mechanisms in InSb
whiskers to explain the magnetoresistance behavior.
The aim of this paper is to study conditions of the nega-
tive magnetoresistance existence in InSb whiskers with Sn
concentration in the vicinity to MIT in the temperature
range 4.2–77 K at magnetic fields 0–14 T.
Experimental procedure
The objects of studies were to observe the behavior of
InSb whiskers with n-type conductivity obtained by the
chemical transport reactions method [11]. Investigated
whiskers were doped by tin during microcrystals growth.
InSb whiskers were selected with length 2–3 mm and lat-
eral dimensions about 30–40 µm. Electrical contacts to
InSb whiskers were created by using Au wires with diame-
ter 10 µm that form an eutectic with the microcrystal under
pulsed welding. This technique was tested and described in
previous works [12] for contact creation to solid solution
SiGe whiskers. It allows measuring whisker resistance
using four contacts scheme.
InSb whisker conductivity was studied in the temperature
range 4.2–300 K. For these studies crystals were cooled to
temperature 4.2 K in the helium cryostat. The temperature
was measured by Cu–CuFe thermocouple calibrated with
CERNOX sensor.
The magnetic field effects of the whiskers was studied
using the Bitter magnet with the induction up to 14 T and
the time scanning of field 1.75 T/min in the temperature
range 4.2–77 K. Stabilized electric current along the
whisker was created by the current source Keithley 224
in the range 1–10 mA depending on the crystal resistance.
CERNOX sensor was used for magnetic measurement, in
particular for its thermostabilization. It is weakly sensitive
to magnetic field induction. The change of its output signal
in the field with induction B = 15 T is about 1%.
All characteristic such as: electrical voltage of the
whisker contacts, output signals from the thermocouple
and the sensor’s magnetic field were measured using the
digital voltmeters type Keithley 199 and Keithley 2000
with precision up to 1⋅10–6 V and simultaneous automatic
registration.
Four groups of n-type InSb whiskers with different dop-
ing concentration (Sn) and varying degrees of approxima-
tion to the critical concentration Ncr = 3⋅1017 cm−3, which
corresponds to the phase metal–insulator transition, were
selected in order to study their magnetoresistance:
— InSb whiskers with the impurity concentration
3.26⋅1017 сm–3 which correspond to MIT;
— InSb whiskers with the impurity concentration
2.3⋅1017 сm–3 in the vicinity of MIT at the dielectric side
of the transition;
— Heavily doped microcrystals with the impurity con-
centration 7.16⋅1017 сm–3 in the vicinity of MIT at metal
side of the transition;
— Lightly doped InSb whiskers with the impurity con-
centration 4.4⋅1016 сm–3 removed from MIT at dielectric
side of the transition.
Experimental results and discussion
Studies of InSb whiskers with different impurity con-
centration (Sn) in the vicinity of MIT in the temperature
range 4.2–77 K at magnetic fields 0–14 T show the occur-
rence of NMR (see Figs. 1–4). A similar behavior of
magnetoresistance, including its reduction in the magnetic
field, was observed for whiskers on the base of other materi-
als, such as p-SiGe solid solution [13] and germanium with
p- and n-type conductivity [14]. The negative magnetoresis-
tance in the InSb whiskers was observed in magnetic field
applied parallel to the crystal axis. NMR reaches about 50%
at the impurity concentration 3.26⋅1017 сm–3 and is observed
at temperatures 4.2–77 K and in the magnetic field 2–14 T
(Fig. 1). Value of the NMR in the InSb whiskers with Sn
582 Low Temperature Physics/Fizika Nizkikh Temperatur, 2016, v. 42, No. 6
Negative magnetoresistance in indium antimonide whiskers doped with tin
concentration in the vicinity of MIT at the metal and die-
lectric side of the transition decreases to 35%, 25% for
concentrations 2.3⋅1017 сm–3, 7.16⋅1017 сm–3 and begins at
magnetic field 3 T, 5 T, accordingly (Figs. 2, 3). The NMR
of the lightly doped InSb whiskers with impurity concen-
tration 4.4⋅1016 сm–3 is revealed in all investigated mag-
netic fields 0–14 T and the longitudinal magnetoresistance
twice crosses the field axis (Fig. 4).
Figure 1 shows the longitudinal magnetoresistance (B
parallel to the wire axis) for InSb whiskers with impurity
concentration 3.26⋅1017 cm–3, which corresponds to MIT
at temperature 4.2 K. The maximum ratio ΔR/R increases
approaching to MIT and reaches 50% at 4.2 K. As the
temperature rise, the maximum value decreases (up to 15%
at temperature 42 K).
The observed NMR effect is like that of the reference
[15] for NiMn/InSb structure. According to data [15] the
NMR cannot be explained by disorder effect [16], and by
the scattering of the conduction electrons by localized
spins through an s–d exchange interaction [17]. An expla-
nation of the NMR is the interface containing microscopic
magnetic entities (NiMn or Ni precipitates). Upon increas-
ing the magnetic field, these magnetic entities gradually
align their magnetic moments with the external magnetic
field leading to a decrease in the spin-dependent resistance
of the system [15].
Noteworthy explanation revealed negative magnetore-
sistance in the field dependences of the investigated longi-
tudinal magnetoresistance in the present work. Possible
reasons for the demonstrated effects may include: 1) the
presence of size quantization in whiskers [18]; 2) the pres-
ence of magnetic ordering of electron spins in InSb whisk-
ers with concentration in the vicinity of metal–insulator
transition [19]; 3) the presence of magnetic ordering in
InSb whiskers by introducing uncontrolled magnetic impu-
rities [20]; 4) quantum interference of electron wave func-
tion [21,22]; 5) classical size effect [23].
The presence of size quantization in InSb whiskers is
excluded due to large transverse dimensions (20–40 µm) of
whiskers (much larger than de Broglie wavelength).
Fig. 1. (Color online) Longitudinal magnetoresistance of InSb
whiskers with impurity concentration 3.26⋅1017 сm–3 at different
temperatures.
Fig. 2. (Color online) Longitudinal magnetoresistance of InSb
whiskers with impurity concentration 2.3⋅1017 cm–3 at different
temperatures.
Fig. 3. (Color online) Longitudinal magnetoresistance of InSb
whiskers with impurity concentration 7.16⋅1017 сm–3 at different
temperatures.
Fig. 4. (Color online) Longitudinal magnetoresistance of InSb
whiskers with impurity concentration 4.4⋅1016 cm–3 at different
temperatures.
Low Temperature Physics/Fizika Nizkikh Temperatur, 2016, v. 42, No. 6 583
A. Druzhinin, I. Ostrovskii, Yu. Khoverko, and N. Liakh-Kaguy
Probable cause of the detected features of InSb whisker
magnetoresistance may be the presence of magnetic order-
ing of electron spins on impurities in heavily doped semi-
conductors. According to well-known model of Y. Toyo-
zawa an appearance of NMR occurs due to reorientation of
spins localized on impurity atoms [19]. As consequence,
one of the possible channel of charge carrier scattering is
excluded leading to magnetoresistance decrease. For ex-
ample, NMR effect was found in Ge whiskers [14]. In InSb
whiskers strong spin-orbital interaction of charge carriers
should occur, which is confirmed by magnetoresistance
splitting and the obtained giant g-factor 45–60 [11].
However, this effect should disappear quickly with the
increase of the temperature above 50 K, where transition
from hopping conductance to classical mechanism of
conductance should take place. Nevertheless, in experi-
ments conducted by this study effect of NMR is observed
at temperatures near 77 K. That is, the presence of NMR
at higher temperatures is so far unclear. Besides at low
temperatures Toyozawa model does not explaine so large
values of NMR.
The presence of magnetic ordering in InSb whiskers
due to introducing magnetic impurities such as Mn, actu-
ally leads to the observation of negative magnetoresistance
in the field dependences of the magnetoresistance [20].
The authors of [20] believe that presence of NMR is de-
pendent on the orientation of spin of electrons scattering on
Mn2+ ions. Results of the present study of elemental con-
tent of impurities in InSb whiskers by microprobe analysis
did not reveal the presence of magnetic impurities in the
samples. Besides, the presence of magnetic impurities in-
teracting with charge carriers is rather doubtful in the
whiskers due to an absence of magnetoresistance peak-
splitting except the one sample corresponding to MIT.
Nevertheless, the investigations of the whisker surface will
be the content of further research of InSb whiskers.
The observed NMR could be explained by quantum
interference of electron wave functions [21,22]. The dis-
appearance of NMR is associated with the destruction of
interference of the electron wave functions by the mag-
netic field. That leads to the effects of weak localization
and electron–electron interaction. These effects at low
spin-orbit interaction result in increase of the resistance.
To determine the presence of quantum interference effects in
the whiskers it is necessary to investigate the behavior of
resistance in the low magnetic fields (up to 1–2 T) and low
temperatures (1.7–4.2 K). Our previous investigation of
InSh whiskers have shown an appearance of SdH oscilla-
tions at low magnetic fields, which indicates in the pres-
ence of quantum interference in the whiskers [10,11].
However, quantum interference effect (small corrections
to the conductivity) could not call so much value of nega-
tive magnetoresistance (of about 50%) as observed in
experiment.
Another explanation of the observed phenomenon was
proposed. First of all, it should be noted the prevalence of
surface conductance in the specimens as compared with bulk
one. This conclusion results from the investigation of longitu-
dinal and transverse resistivity of the whiskers (see Fig. 5). As
follows from Fig. 5, transverse resistivity (curve 4) is signifi-
cantly lesser than longitudinal one (curve 1). This can be ex-
plained by the prevalence of surface conductance in transverse
specimen geometry. The similar phenomenon was observed
in Si whiskers, where increase of dopant impurities approach-
ing the whisker surface was revealed [24].
One can suppose that the same mechanism of the
whisker growth by chemical vapour deposition in halogen
closed system leads to the similar whisker doping by impu-
rities during the growth process. The second reason of in-
crease of doping impurity near the whisker surface may be
diffusion of impurities to the surface during the sample
annealing after their growth.
If assumption of the prevalence of surface conductance
in the whisker is true, i.e., the main part of charge carriers
transport takes place in subsurface region of the whisker,
which can be characterized by effective wire radial dis-
tance, one can suggest the following explanation of nega-
tive magnetoresistance in the InSb whiskers. The MR
peaks in Fig. 2 are due to the classical size effect, where
the wire boundary scattering is reduced as the cyclotron
radius becomes smaller than the effective wire radial dis-
tance, resulting in a decrease in the resistivity. The simi-
lar behavior is typical for the longitudinal MR of Bi
nanowires in the diameter range dW = 45–200 nm, while
the peak position Bm varies linearly with 1/dW as the wire
diameter increases [23]. The condition for the occurrence
of Bm is given approximately by Bm ≈ 2ckF/ЕdW, where
kF is the wavevector at the Fermi energy [23]. Taking
into account the obtained Fermi energy Е, one can calcu-
late the effective wire radial distance, which for InSb
whiskers is about 250 nm.
Fig. 5. (Color online) Dependences of longitudinal (1–3) and trans-
verse (4) resistivity versus temperature for InSb whiskers with vari-
ous impurity concentrations: 3.26⋅1017 сm–3 (1, 4), 2.3 ⋅1017 сm–3 (2),
7.16⋅1017 сm–3 (3).
584 Low Temperature Physics/Fizika Nizkikh Temperatur, 2016, v. 42, No. 6
Negative magnetoresistance in indium antimonide whiskers doped with tin
The peak position Bm is found to increase linearly with
increasing temperature in the range of 4.2–60 K, as shown
in Fig. 2. At an increase of temperature phonon scattering
becomes more important and leads to shift of the Bm peak
position. When the whisker impurity concentration is re-
moved from MIT (as at dielectric and metal side of MIT) a
decrease of NMR peak is observed.
The decrease of the magnetoresistance peak may be at-
tributed to a rise of effective radial distance approaching
effective wire radial distance, much longer than the carrier
mean free path. The negative MR observed for the InSb
whiskers above Bm (Figs. 2, 3) shows that wire boundary
scattering is a dominant scattering process for the longitu-
dinal magnetoresistance, establishing that the mean free
path is larger than the effective wire radial distance.
To check the size effect in the magnetoresistance of InSb
whiskers the Larmor radius of the electron trajectories was
calculated in the range of magnetic field 0–14 T according to
the model described in the work [25]. It decreases with in-
creasing induction in all range. So, the Larmor radius is larger
than the effective wire radial distance in magnetic fields up to
2–3 T and it changes from 1 µm to 200 nm. These two pa-
rameters are equal to each other at the magnetic induction 4 T.
The Larmor radius is less than the radial distance at the higher
magnetic fields, and it consists 77 nm at 14 T. As follows, the
contribution of size effect on the behavior of magnetoresis-
tance was observed: in the magnetic fields up to 2–4 T strong
boundary scatterring occurs leading to rapid growth of mag-
netoresistance. When Larmor radius becomes less that effec-
tive wire radial distance, then magnetoresistance decreases
rapidly caused by decreasing in the boundary scattering.
Conclusions
It is established that longitudinal magnetoresistance of all
investigated samples changes sign with increase of magnetic
field: it is positive in the magnetic fields up to 2–4 Т and it
becomes negative at higher magnetic fields. The large nega-
tive magnetoresistance as well as the change of magnetoresis-
tance sign were discussed due to following possible mecha-
nisms: 1) presence of carrier quantization in the whiskers;
2) presence of magnetic ordering due to superposition of
electron spins; 3) presence of magnetic ordering due to
introducing uncontrolled magnetic impurities in the whisk-
ers; 4) quantum interference of electron wave functions; 5)
classical size effect.
The contribution of all the above terms were discussed and
it was proposed that dominant reason of large NMR and
change of MR sign could be due to the existence of classical
size effect, in particular boundary scattering during their con-
ductance in thin (of about 250 nm) subsurface layer of the
whiskers. Presence of quantum interference of electron wave
functions as well as magnetic ordering due to superposition of
electron spins on impurities leads to nonessential contribution
to observed NMR in the whiskers.
1. S. Ishida, K. Takeda, A. Okamoto, and I. Shibasaki, Physica
E 20, 255 (2004).
2. S. Ishida, K. Takeda, A. Okamoto, and I. Shibasaki, 10th
Conf. on Hopping and Related Phenomena, International
Centre for Theoretical Physics, September 1–4, 2003, p. 1–7.
3. E. Lahderanta, A.V. Lashkul, A.V. Kochura, S.G. Lisunov,
B.A. Aronzon, and M.A. Shakhov, Phys. Status Solidi A 211,
991 (2014).
4. A. Kochura, Growth, Magnetic and Transport Properties of
InSb and II-IV-As2 Semiconductors Doped with Manganese,
Diss. Lappeenranta University of Technology, Lappeenranta
(2011).
5. S.A. Obukhov, S.W. Tozer, and W.A. Coniglio, Sci. Rep. 5,
13451 (2015).
6. S.A. Obukhov, Phys. Status Solidi C 9, 247 (2012).
7. O.V. Kirichenko and V.G. Peschanskii, Fiz. Nizk. Temp. 37,
925 (2011) [Low Temp. Phys. 37, 734 (2011)].
8. N.A. Viglin, V.V. Ustinov, V.M. Tsvelikhovskaya, and O.F.
Denisov, JETP Lett. 84, 79 (2006).
9. J. Teubert, S.A. Obukhov, P.J. Klar, and W. Heimbrodt,
J. Phys. Rev. Lett. 102, 046404 (2009).
10. A. Druzhinin, I. Ostrovskii, Yu. Khoverko, N. Liakh-Kaguy,
I. Khytruk, and K. Rogacki, Mater. Res. Bull. 72, 324
(2015).
11. A. Druzhinin, I. Bolshakova, I. Ostrovskii, Yu. Khoverko, and
N. Liakh-Kaguy, Mater. Sci. Semicond. Proc. 40, 550 (2015).
12. A.A. Druzhinin, I.P. Ostrovskii, N.S. Liakh, and S.M.
Matvienko, Journal of Physical Studies 9, 71 (2005).
13. A.A. Druzhinin, I.P. Ostrovskii, Yu.M. Khoverko, N.S.
Liakh-Kaguj, and Iu.R. Kogut, Mater. Sci. Semicond. Proc.
14, 18 (2011).
14. A.A. Druzhinin, I.P. Ostrovskii, Yu.N. Khoverko, N.S. Liakh-
Kaguy, and A.M. Vuytsyk, Funct. Mater. 21, 130 (2014).
15. S. Gardelis, J. Androulakis, Z. Viskadourakis, E.L.
Papadopoulou, J. Giapintzakis, S. Rai, G.S. Lodha, and S.B.
Roy, Phys. Rev. B 74, 214427 (2006).
16. R.G. Mani, L. Ghenim, and J.B. Choi, Phys. Rev. B 43,
12630 (1991).
17. Y. Katayama and S. Tanaka, Phys. Rev. 153, 873 (1967).
18. A.A. Nikolaeva, L.A. Konopko, A.K. Tsurkan, E.P. Sinyavskii,
and O.V. Botnari, Surf. Eng. Appl. Electrochem. 51, 45 (2015).
19. Y. Toyozawa, J. Phys. Soc. Jpn. 17, 986 (1962).
20. A.V. Kochura, B.A. Aronzon, and M. Alam, J. Nano and
Electronic Physics 5, 04015-1 (2013).
21. B.L. Altshuler, A.G. Aronov, A.I. Larkin, and D.E.
Khmel’nitskii, JETP 54, 2, 411 (1981).
22. P.A. Lee and T.V. RamaknShnan, Rev. Mod. Phys. 53, 287
(1985).
23. Z. Zhang, X. Sun, M.S. Dresselhaus, J.Y. Ying, and J.
Heremans, Phys. Rev. B 61, 4850 (2000).
24. A. Druzhinin, I. Ostrovskii, Y. Khoverko, and R. Koretskii,
Mater. Sci. Semicond. Proc. 40, 766 (2015).
25. Yu.P. Gaidukov and E.M. Golyamina, JETP 48, 719 (1978).
Low Temperature Physics/Fizika Nizkikh Temperatur, 2016, v. 42, No. 6 585
http://dx.doi.org/10.1016/j.physe.2003.08.013
http://dx.doi.org/10.1016/j.physe.2003.08.013
http://indico.ictp.it/event/a0278/session/33/contribution/23/material/0/0.pdf
http://indico.ictp.it/event/a0278/session/33/contribution/23/material/0/0.pdf
http://dx.doi.org/10.1002/pssa.201300721
http://dx.doi.org/10.1038/srep13451
http://dx.doi.org/10.1002/pssc.201100291
http://dx.doi.org/10.1063/1.3665891
http://dx.doi.org/10.1134/S0021364006140086
http://dx.doi.org/10.1103/PhysRevLett.102.046404
http://dx.doi.org/10.1016/j.materresbull.2015.08.016
http://dx.doi.org/10.1016/j.mssp.2015.07.030
http://physics.lnu.edu.ua/jps/2005/1/pdf/71_74.pdf
http://dx.doi.org/10.1016/j.mssp.2010.12.012
http://dx.doi.org/10.1016/j.mssp.2010.12.012
http://dx.doi.org/10.15407/fm21.02.130
http://dx.doi.org/10.1103/PhysRevB.74.214427
http://dx.doi.org/10.1103/PhysRevB.43.12630
http://dx.doi.org/10.1103/PhysRev.153.873
http://dx.doi.org/10.3103/S106837551501010X
http://dx.doi.org/10.1143/JPSJ.17.986
http://dx.doi.org/10.1103/%20RevModPhys.57.287
http://dx.doi.org/10.1103/PhysRevB.61.4850
http://dx.doi.org/10.1016/j.mssp.2015.07.015
Introduction
Experimental procedure
Experimental results and discussion
Conclusions
|