Crystal growth and thermal properties of binary borates, Ca3RE2(BO3)4 (RE = Y, Gd, Nd), are considered promising crystals for laser applications. These single crystals were grown by the Czochralski ...method. The crystal and defect structure were characterized. Volumetric chemical methods without prior separation of the components were developed and applied for the determination of the dependence of chemical compositions of the crystals on the growth conditions. The thermal conductivity was investigated in the 50–300 K range. The character of the temperature dependence of thermal conductivity was found to be similar to that of glass. The possible reasons of the observed features of the thermal conductivity were analyzed.
Thermal conductivities of
M
WO
4
(
M
= Ca, Cd, or Ba), NaGd(WO
4
)
2
:1 at % Er, NaGd(WO
4
)2:2 at % Yb, and NaLa
0.5
Gd
0.5
(WO
4
)
2
:2 at % Nd single crystals have been experimentally investigated ...in the temperature range of 50–300 K.
The thermal conductivity of a ZnWO
4
single crystal in the principal crystallographic directions has been studied experimentally in the temperature range of 50–573 K, and the heat capacity of the ...single crystal has been measured in the range of 81–301 K.
The
Ca
9
RE
(
VO
4
)
7
(RE
=
La, Nd, Gd) and
Ca
10
M
(
VO
4
)
7
(M
=
Li, Na, K) single crystals have been grown by the Czochralski method. The binary vanadates are isostructural to “whitlockite” ...mineral (rhombohedral symmetry,
R
3
c
space group). Their thermal conductivity has been investigated in the range 50 K–300 K parallel to the
c
axis. For
Ca
9
Gd
(
VO
4
)
7
crystals, the thermal conductivity has been investigated in the range 300 K–550 K also. Additionally, for the
Ca
10
M
(
VO
4
)
7
(M
=
Li, Na, K) crystals the heat capacity has been studied in the temperature range 80 K–300 K. The character of the temperature dependence of thermal conductivity is close to that of glasses. The possible reasons of the observed features of the thermal conductivity have been analyzed. Raman spectra of
Ca
10
M
(
VO
4
)
7
(M
=
Li, Na, K) crystals have been measured and discussed. The spectral lines were broad and similar to polycrystalline or amorphous solids. These crystals are expected to be suitable for application as efficient nonlinear optic and laser materials.
The Ca9RE(VO4)7 (RE = La, Nd, Gd) and Ca10M(VO4)7 (M = Li, Na, K) single crystals have been grown by the Czochralski method. The binary vanadates are isostructural to “whitlockite” mineral ...(rhombohedral symmetry, R3c space group). Their thermal conductivity has been investigated in the range 50 K–300 K parallel to the c axis. For Ca9Gd(VO4)7 crystals, the thermal conductivity has been investigated in the range 300 K–550 K also. Additionally, for the Ca10M(VO4)7 (M = Li, Na, K) crystals the heat capacity has been studied in the temperature range 80 K–300 K. The character of the temperature dependence of thermal conductivity is close to that of glasses. The possible reasons of the observed features of the thermal conductivity have been analyzed. Raman spectra of Ca10M(VO4)7 (M = Li, Na, K) crystals have been measured and discussed. The spectral lines were broad and similar to polycrystalline or amorphous solids. These crystals are expected to be suitable for application as efficient nonlinear optic and laser materials.
Thermal conductivity of Na2W2O7 crystal Popov, P. A.; Skrobov, S. A.; Mitroshenkov, N. V. ...
Physics of the solid state,
08/2016, Letnik:
58, Številka:
8
Journal Article
Recenzirano
The thermal conductivity of Na
2
W
2
O
7
single crystal has been studied along the main crystallographic directions at temperatures of 50–573 K. A low thermal conductivity is found to correlate with ...a significant difference in the cation weight.
Thermophysical characteristics of SrMoO
4
crystals (grown by the Czochralski method from intrinsic melts), nominally pure and doped with rare earth ions, have been investigated. The temperature and ...concentration dependences of the thermal conductivity are obtained for SrMoO
4
samples containing Nd
3+
(0.28, 0.56, 0.84, and 1.33 at %), Pr
3+
(0.01 and 0.41 at %), Ho
3+
(0.01 and 0.06 at %), and Ho
3+
(0.13 at %) + Tm
3+
(0.13 at %) in a temperature range of 50–300 K. The thermal conductivities are measured in the directions parallel and/or perpendicular to the crystal optical axis. The thermal conductivity of nominally pure SrMoO
4
at 300 K in the direction perpendicular to the
c
axis has been found to be 4.2 W/(m K). The introduction of impurities of rare earth metals reduces the thermal conductivity of SrMoO
4
crystals. The anisotropy of the thermal conductivity is weak. The measured molar specific heat
C
P
(
T
) of a nominally pure SrMoO
4
crystal is 116.2 J/(mol K) at 300 K. The temperature dependence of the phonon mean free path
l
(
T
) in a SrMoO
4
crystal is calculated for the temperature range of 80-300 K based on experimental data.
The thermal conductivity of single-crystal samples of Sr
0.88
La
0.09
Nd
0.03
F
2.03
and Sr
0.80
La
0.15
Nd
0.05
F
2.20
solid solutions, both with a cellular substructure and without it, have been ...investigated by the method of stationary longitudinal heat flow in the temperature range of 50–300 K. An anisotropy of thermal conductivity (related to the substructure) is established for a Sr
0.995
Nd
0.005
F
2.005
single crystal.
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