Influence of high hydrostatic pressure on energetic structure and electron-lattice coupling of transition metal and rare earth related centers in solids
We present the results of the photoluminescence of the crystals doped with transition metals or rare earth ions obtained under high hydrostatic pressure up to 300 kbar applied in diamond anvil cells (DAC). We have focused on Al₂O₃, YAlO₃ LLGG and YAG garnets and LiNbO₃, and LiTaO₃ perovskites doped...
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Grinberg, M. Barzowska, J. Gryk, W. 2017-05-29T05:34:12Z 2017-05-29T05:34:12Z 2004 Influence of high hydrostatic pressure on energetic structure and electron-lattice coupling of transition metal and rare earth related centers in solids / M. Grinberg, J. Barzowska, W. Gryk // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2004. — Т. 7, № 2. — С. 180-184. — Бібліогр.: 30 назв. — англ. 1560-8034 PACS: 61.72.Ss, 78.60.-b https://nasplib.isofts.kiev.ua/handle/123456789/118171 We present the results of the photoluminescence of the crystals doped with transition metals or rare earth ions obtained under high hydrostatic pressure up to 300 kbar applied in diamond anvil cells (DAC). We have focused on Al₂O₃, YAlO₃ LLGG and YAG garnets and LiNbO₃, and LiTaO₃ perovskites doped with Cr³⁺, Ti³⁺ and Ce³⁺. We have observed the pressure induced red shift of the df emission in the case of materials doped with Ce and blue shift of the ⁴T₂⁴A₂ and ²E²T₂ emission in the case of materials doped with Cr³⁺ and Ti³⁺, respectively. Considering our experimental data we have calculated the local compresibilities of the materials and found that almost in all cases this quantity is smaller than compressibility of the bulk. This work was supported bу Polish State Committee for Scientific Researches bу Grant No 2PО3 ВО57 23. en Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України Semiconductor Physics Quantum Electronics & Optoelectronics Influence of high hydrostatic pressure on energetic structure and electron-lattice coupling of transition metal and rare earth related centers in solids Article published earlier |
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Influence of high hydrostatic pressure on energetic structure and electron-lattice coupling of transition metal and rare earth related centers in solids |
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Influence of high hydrostatic pressure on energetic structure and electron-lattice coupling of transition metal and rare earth related centers in solids Grinberg, M. Barzowska, J. Gryk, W. |
| title_short |
Influence of high hydrostatic pressure on energetic structure and electron-lattice coupling of transition metal and rare earth related centers in solids |
| title_full |
Influence of high hydrostatic pressure on energetic structure and electron-lattice coupling of transition metal and rare earth related centers in solids |
| title_fullStr |
Influence of high hydrostatic pressure on energetic structure and electron-lattice coupling of transition metal and rare earth related centers in solids |
| title_full_unstemmed |
Influence of high hydrostatic pressure on energetic structure and electron-lattice coupling of transition metal and rare earth related centers in solids |
| title_sort |
influence of high hydrostatic pressure on energetic structure and electron-lattice coupling of transition metal and rare earth related centers in solids |
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Grinberg, M. Barzowska, J. Gryk, W. |
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Grinberg, M. Barzowska, J. Gryk, W. |
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2004 |
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English |
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Semiconductor Physics Quantum Electronics & Optoelectronics |
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Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України |
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Article |
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We present the results of the photoluminescence of the crystals doped with transition metals or rare earth ions obtained under high hydrostatic pressure up to 300 kbar applied in diamond anvil cells (DAC). We have focused on Al₂O₃, YAlO₃ LLGG and YAG garnets and LiNbO₃, and LiTaO₃ perovskites doped with Cr³⁺, Ti³⁺ and Ce³⁺. We have observed the pressure induced red shift of the df emission in the case of materials doped with Ce and blue shift of the ⁴T₂⁴A₂ and ²E²T₂ emission in the case of materials doped with Cr³⁺ and Ti³⁺, respectively. Considering our experimental data we have calculated the local compresibilities of the materials and found that almost in all cases this quantity is smaller than compressibility of the bulk.
|
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1560-8034 |
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https://nasplib.isofts.kiev.ua/handle/123456789/118171 |
| citation_txt |
Influence of high hydrostatic pressure on energetic structure and electron-lattice coupling of transition metal and rare earth related centers in solids / M. Grinberg, J. Barzowska, W. Gryk // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2004. — Т. 7, № 2. — С. 180-184. — Бібліогр.: 30 назв. — англ. |
| work_keys_str_mv |
AT grinbergm influenceofhighhydrostaticpressureonenergeticstructureandelectronlatticecouplingoftransitionmetalandrareearthrelatedcentersinsolids AT barzowskaj influenceofhighhydrostaticpressureonenergeticstructureandelectronlatticecouplingoftransitionmetalandrareearthrelatedcentersinsolids AT grykw influenceofhighhydrostaticpressureonenergeticstructureandelectronlatticecouplingoftransitionmetalandrareearthrelatedcentersinsolids |
| first_indexed |
2025-11-26T22:50:03Z |
| last_indexed |
2025-11-26T22:50:03Z |
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1850778990069940224 |
| fulltext |
Semiconductor Physics, Quantum Electronics & Optoelectronics. 2004. V. 7, N 2. P. 180-184.
© 2004, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine180
PACS: 61.72.Ss, 78.60.-b
Influence of high hydrostatic pressure on energetic
structure and electron-lattice coupling of transition metal
and rare earth related centers in solids
M. Grinberg*, J. Barzowska, W. Gryk
Institute of Experimental Physics, University of Gdansk, Wita Stwosza 57, 80-952 Gdansk, Poland
Abstract. We present the results of the photoluminescence of the crystals doped with transi-
tion metals or rare earth ions obtained under high hydrostatic pressure up to 300 kbar ap-
plied in diamond anvil cells (DAC). We have focused on Al2O3, YAlO3 LLGG and YAG
garnets and LiNbO3, and LiTaO3 perovskites doped with Cr3+, Ti3+ and Ce3+. We have
observed the pressure induced red shift of the d→f emission in the case of materials doped
with Ce and blue shift of the 4T2→4A2 and 2E→2T2 emission in the case of materials doped
with Cr3+ and Ti3+, respectively. Considering our experimental data we have calculated the
local compresibilities of the materials and found that almost in all cases this quantity is
smaller than compressibility of the bulk.
Keywords: high pressure spectroscopy, Ce3+, Cr3+, Ti3+, garnets, perovskites, elastic proper-
ties, electron -lattice coupling
Paper received 09.03.04; accepted for publication 17.06.04.
1. Introduction
Luminescent solid state materials comprised of insulat-
ing host lattices (normally oxides, chlorides and fluo-
rides) activated by rare earth and transition metal ions
continue to be an active area of research. These materi-
als are desirable for practical applications for several
reasons including mechanical strength, durability, chemi-
cal inertness, portability, frequent ease of chemical syn-
thesis, and diversity of properties. All considered materi-
als are characterized by the broad band gap (10 eV) [1].
The activity arises from the promise in areas such as solid
state lasers, optical communications, scintillation, medi-
cal procedures, imaging, displays, flow cytometry, ho-
lography, and remote sensing [2�3].
Transition metals and rare earth ions contribute to
the energetic structure of the system via localized states
with energies inside the forbidden gap of the host materi-
als. These states are occupied by the electrons from the
unfilled internal electronic shells 3dn (1 ≤ n ≤ 10) in the
case of transition metals and 4fn or 4fn�15d1(1 ≤ n ≤ 14) in
the case of rare earths. Although 3d and 5d electrons are
localized at the transition ion, they extend enough to
interact with the nearest neighbor host ions. As a result,
the energetic structure of transition metals and rare earths
is different in different hosts.
The sensitivity of the energetic structure of transition
ions on the host caused our interests in high pressure
spectroscopy of these systems. The high hydrostatic pres-
sure applied in the diamond anvil cell (DAC) diminishes
the distance between the ion and ligands. As a conse-
quence, the influence of ligands on localized electrons is
stronger. High pressure spectroscopy has been exten-
sively applied for the investigation of 3d�3d optical tran-
sitions in transition metal ions in solids [4�5]. One can
find the review of earlier works on this topic in [4]. The
author of this paper has used high pressure spectroscopy
for characterization of Cr3+ ions in LiNbO3, LiTaO3
crystals [6�9] and garnet crystals [10] as well as glasses
[11]. In recent years, high pressure has been used for
investigation of the emission related to 4fn�15d1→4fn tran-
sitions [12�14]. In this contribution, we summarize our
investigations on high pressure spectroscopy of Ti3+, Ce3+
and Cr3+ ions in various materials.
M. Grinberg et al.: Influence of high hydrostatic pressure on energetic structure �
181SQO, 7(2), 2004
2. Experimental results
2.1 High pressure spectroscopy of Ti3+ and Ce3+
The simplest energetic structure have the Ti3+ and Ce3+
ions. It is determined by singe electron that occupies the
terms belonging to the 3d1 electronic configuration and
4f1or 5d1 electronic configurations in the case of Ti3+ and
Ce3+, respectively. We have investigated Ti doped Al2O3
and YAlO3 crystals. In both materials Ti3+ substitutes
Al3+ ion in octahedral coordination of the six O2� ligands.
According to the crystal field theory [15], the 3d1 state is
splitted into the 2E and 2T2 states, energies of which are
given by:
DqEE 6)( 2 = (1)
DqTE 4)( 2
2 −= (2)
Crystal field strength parameter depends on the cen-
tral ion-ligand distance according to relation naDq −∝
where exponent and depends on the nature of ligands.
We have investigated the Ce3+ ions incorporated in
the Y3Al5O12 and Gd3Sc2Al3O12. In these hosts the Ce3+
ions occupy the dodecahedrally coordinated Y3+ and
Gd3+ positions, respectively. In both cases the ground
electronic configurations 4f1 splits due to strong spin-
orbit interaction into the 2F7/2 ground state and 2F5/2
excited state. It is assumed further that electron in these
state is well screened from interaction with the ligands.
The excited electronic configuration that is 5d1 interacts
with the lattice in the same way as the 3d1, thus for
dodecahedrally coordinated system the 5d1 splits into the
2E and 2T2 states that energies are given by:
DqEE
3
16
)(2 −= (3)
DqTE
9
32
)( 2
2 = (4)
The energetic structure of these two systems is pre-
sented in Fig. 1,a and b. Actually, the energy of the low-
est state of the 5d1 electronic configuration of the Ce3+
ion in lattice is diminished by the quantity of depression
energy Edepr [16]:
cendepr EDqE +−=
3
16
(5)
where Ecen is the centroid shift related to changes in the
ligands polarization that accompanies 4f1�5d1 transition.
One considers that
nQ
Dq
1
∝
(6)
and
'
1
ncen
Q
E ∝
(7)
In the standard crystal field model [17], n = 5, whe-
reas according to the ligands polarization model [18],
n' = 6.
According to the Fig. 1 a and b, one expects that pres-
sure induces a blue shift of the emission of the Ti3+ and a
red shift of the emission of the Ce3+. Actually such shifts
have been observed. Typical emission spectra are pre-
sented in Fig. 2,a and b. One can see that the spectral
lineshape almost does not depend on pressure. One no-
tices that maxima of the emission bands shift linearly
with pressure. Thus, one can describe these shifts by re-
spective pressure coefficients. Table 1 contains data ob-
tained for Ce3+ and Ti3+ ions. Here the pressure shifts of
the absorption maxima of the lowest absorption band for
some materials are presented.
2.2. High pressure spectroscopy of Cr3+
Cr3+ ion occupies usually octahedrally coordinated sites.
Energetic structure of the lowest states of the Cr3+ system
is presented is presented in Fig. 1,c. One can see that
depending on the crystal field strength the firs excited
state is the 4T2 or 2E. In the low field systems, the 4T2
state has lower energy than the 2E state and Cr3+ exhibits
broad band emission related to the 4T2 → 4A2 transi-
tion. In the high field case, the 2E state is lower in energy
and sharp, structured (R-lines) emission relate to 2E →
→ 4A2 transition is observed. Energy of the 4T2 state
with respect of the ground state is equal to 10Dq. Thus
similarly like in the case of Ti3+ in the case of the Cr3+
system one expects pressure induced blue shift of the 4T2
4A2 emission band. Luminescence spectra of the
LiTaO3:Cr3+ obtained for different pressure are pre-
sented in Fig. 2,c. In Table 1, the pressure blue shift of
4T2 → 4A2 emission band in various crystals doped with
Cr3+ are summerized.
Fig. 1. Energetic structure of the Ti3+ ion in octahedral position
(a), Ce3+ In dodecahedral position (b) and Cr3+ in the octahe-
dral position (c). For the Cr3+ only the 4A2, 4T2 and 2E states are
presented.
a
3d
5d
E
E10Dq
80/9Dq
4f
T
T
T
E
10Dq
A
F
F
1
1
1
2
2
2
2
2
2
2
2
2
2
2
4
4
5/2
7/2
b c
182
SQO, 7(2), 2004
M. Grinberg et al.: Influence of high hydrostatic pressure on energetic structure �
3. Discussion
One considers that pressure causes an increase of crystal
field according to relation
B
K
nDq
dp
da
a
nDq
dp
dDq
3
1
=−= , (8)
where B is the bulk moduli of material. The dimensionless
coefficient K
0
0
da
da
a
a
K = , (9)
where a0 and a is the lattice constant and central ion-
ligand distance, respectively, describes the way in which
the macroscopic effect of pressure modifies the local en-
vironment of the central ion. K = 1, K < 1 and K > 1
means that the compression of the ion-ligand system is
the same, smaller and larger than compression of the
bulk lattice.
Since, in the excited state, the system is characterized
by another distribution of electron charge than that in
the ground state, after excitation the lattices ions shift a
little to adapt to the new charge distribution. As a result,
lattice relaxes and total energy of the system diminishes.
The situation is described by configurational coordinate
diagram presented in Fig. 3. The energy of lattice rela-
xation ωhS may also depend on pressure. Thus, one ob-
tains
dp
dS
dp
dE
dp
dE emabs ωh
2+= . (10)
In the case of the Ti3+ and Cr3+ systems, one can re-
late the pressure changes of the absorption peak to the
pressure changes of the crystal filed strength by
B
nK
Dq
dp
dDq
dp
dEabs
3
1010 == . (11)
Usually it is difficult to measure pressure dependence
of the absorption spectrum. Therefore, instead of absorp-
tion we use the emission. Neglecting the dependence of
the lattice relaxation energy on pressure, one obtains:
B
nK
Dq
dp
dDq
dp
dEem
3
1010 == . (12)
In the case of Ce3+, one can consider the relation:
B
nK
E
dp
dE
depr
abs
3
−≈ , (13)
that is valid under condition that exponents (in relations
(6) and (7)) are very similar; 'nn ≈ . Relations (11) and
(13) allows to calculate quantity nK. Than assuming that
the exponent value is known, one can calculate the local
compressibility K. The results of calculations are listed
in Table 1. One can see that almost in all the cases quan-
tity nK is significantly smaller than 5. The exception is
YAlO3:Ti3+ system.
Table. 1. Spectroscopic data and calculated parameters for transition metal and rare earth ions in different materials
Material Edepr, Eem, dEem/dp, Eabs, dEabs/dp, B, nK
[16] cm�1 cm�1/kbar cm�1 cm�1/kbar kbar
cm�1
YAG:Ce3+ 27570 19100±100 �12.5±0.7 21750±100 �12.5 0.7 1870 [19] 2.85 *
[14] 17560±100 �11.8 0.7
�8.3 0.5
GSAG:Ce3+ 2 7000 17340±100 �7.5 0.5 22320±100 �15.2 0.7 1916** 2.67
15250±100 13 2[20]
LLGG:Cr3+ 11700 [20] 5.40 [5] 15033[20,21] 8.4 3 [24] 1330[22,23] 3.45 (3.88)
Al2O3:Cr3+ 14790 *** 5.93 [5] 17950 50[24] 6.96 [5] 2420 [25] 3.41 (3.71)
Al2O3:Ti3+ 13670 [5] 20590 [5] 8.52 [5] 2420 [25] 2.98
12450 [5] 19.6 [26] 17690 [5]
YAlO3:Ti3+ 16330 [26] 13.5 22880 [26] 2004 [27] 5.44
13.5[9] 20400 [26]
LiNbO3:Cr3+ 10800 15000 1058 [28] 2.85 (3.31)
LiTaO3:Cr3+ 11020 15820 1057 [28] 2.7 (3.22)
YAG:Cr3+ 16500 [29] 9****[29] 1870 [19] 3.06
* These data were calculated under assumption that pressure absorption and emission pressure coefficients are the same.
** The calculated here bulk moduli were taken from [30]
*** These data were calculated from the values of the absorption maximum and electron-lattice coupling energy ωhS in
accordance with the following relation
ωhSEE absem 2−=
****The pressure shift was calculated from the analysis of R line lifetime dependence on pressure
M. Grinberg et al.: Influence of high hydrostatic pressure on energetic structure �
183SQO, 7(2), 2004
4. Conclusions
We have discussed the dependence of d-d and d-f transi-
tion energies in the case of Ti3+, Cr3+ and Ce3+ on the
high hydrostatic pressure. Using the crystal field ap-
proach, we have related the pressure rates energy of the
respective emission and absorption bands on comp-
ressibility (elastic moduli) of the material. In all the cases,
apart of YAlO3:Ti3+, we have found that the compres-
sibility of the dopant local environment is almost two
times less than the compressibility of bulk materials. In
the exceptional case, this local compressibility and the
bulk one possess practically the same value.
Acknowledgements
This work was supported by Polish State Committee for
Scientific Researches by Grant No 2P03 B057 23.
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