|
XXI All-Russian School-Seminar on Condensed Matter Physics (SPFKS-21), Yekaterinburg, March 18-25, 2021
Thermal properties
Thermal and magnetocaloric properties of manganites La$_{0.7}$Sr$_{0.3-x}$Ba$_{x}$MnO$_{3}$
A. B. Gadzhieva, A.G. Gamzatova, A. B. Batdalova, Z. A. Hurshilovab, A. M. Alieva a Daghestan Institute of Physics after Amirkhanov
b Dagestan State Medical University, Makhachkala
Abstract:
The results of a study of the effect of partial substitution of Sr$^{2+}$ ions by Ba$^{2+}$ ions on the thermophysical and magnetocaloric properties of manganite La$_{0.7}$Sr$_{0.3-x}$Ba$_{x}$MnO$_{3}$ ($x$ = 0; 0.02; 0.05 and 0.10) in the temperature range 100–400 K and in a magnetic field up to 1.8 T. It is shown that such a substitution leads to a significant decrease in $T_C$. In the behaviour of the thermal diffusivity $\eta(T)$ and thermal conductivity $\kappa(T)$ near $T_C$, minima were found that are associated with both the scattering of phonons by local distortions of the crystal lattice and by spin fluctuations. The absolute values of thermal conductivity decrease with an increase in the disorder parameter. The magnetocaloric effect exhibits a weak dependence on the substitution level $(x)$.
Keywords:
magnetocaloric effect, manganites, phase transitions, heat capacity, thermal diffusivity, thermal conductivity.
Received: 08.07.2021 Revised: 13.07.2021 Accepted: 16.07.2021
Citation:
A. B. Gadzhiev, A.G. Gamzatov, A. B. Batdalov, Z. A. Hurshilova, A. M. Aliev, “Thermal and magnetocaloric properties of manganites La$_{0.7}$Sr$_{0.3-x}$Ba$_{x}$MnO$_{3}$”, Fizika Tverdogo Tela, 63:12 (2021), 2028–2032
Linking options:
https://www.mathnet.ru/eng/ftt7910 https://www.mathnet.ru/eng/ftt/v63/i12/p2028
|
Statistics & downloads: |
Abstract page: | 111 | Full-text PDF : | 25 |
|