THE EFFECT OF A-SITE CATION VARIANCE ON THE THERMAL PROPERTIES OF HALF-DOPED PEROVSKITE MANGANITES
We investigate here the thermodynamic properties of orthorhombic half-doped perovskite rare earth manganites R0.5Ca0.5MnO3 (R=La, Pr, NdDy) by incorporating the effect of A-site cation variance. The strong electron-phonon interactions of these compounds are affected by lattice distortions due to A-site size variance and charge mismatch (between Ca and R). In the half-doped manganites the cation size variance reaches its maximum and affects the A-O environment to maximize the distortions and the lattice specific heat increases appreciably. The lattice contributions to the specific heat at constant volume (Cv (lattice)) of R0.5Ca0.5MnO3 has been studied as a function of temperature (10K≤T≤300K) by means of a Modified Rigid Ion Model (MRIM) and are found to be in agreement with the published data. The Debye temperatures obtained from the lattice contributions are also in somewhat closer agreement with the available experimental data. Some other elastic, cohesive and thermal properties like bulk modulus (B), cohesive energy (Φ), molecular force constant (f), Reststrahlen frequency (νo) and Gruneisen parameter (γ) are also presented.
Jyotsana Galgale Archana Srivastava N. K. Gaur
Department of Physics Sri Sathya Sai College for Women Bhopal, India, 462024 Department of Physics Barkatullah University Bhopal, India, 462026
国际会议
The Ninth Asian Thermophysical Properties Conference(第九届亚洲热物理性能会议 ATPC 2010)
北京
英文
756-762
2010-10-19（万方平台首次上网日期，不代表论文的发表时间）