INVESTIGATION OF LATTICE DISTORTIONS IN ELECTRON DOPED CaMnO3 AND ITS RELATION TO THE THERMAL PROPERTIES
We have investigated the thermal properties of A-site doped perovskite CaMnO3, the end member (n=∞) of the Ruddlesden-Popper (RP) calcium manganates series. The effect of lattice distortions on the elastic and thermal properties of these electron doped manganites is investigated using an atomistic approach. The specific heat of Ca1-xLnxMnO3 (x=0.10, 0.20) with Ln (=La, Pr, Nd, Sm, Eu, Gd, Th, Bi) doping at the A-site has been studied as a function of temperature (10K<T<300K) by means of a Rigid Ion Model (RIM) after modifying its framework to incorporate the van der Waals interactions. Strong electron-phonon interactions are present in these compounds which causes the variation of the lattice specific heat (Cv (lattice)) by cation doping of varying size and valence. The relation between Jahn-Teller distortion and Debye temperature, obtained from the lattice contributions, is reported probably for the first time. The specific heat values revealed by using RIM are in closer agreement with the available experimental data for some compositions (x) of Ca1-xLnxMnO3. In addition, the results on the cohesive energy (Φ), molecular force constant (f), Reststrahlen frequency (νo) and Grüneisen parameter (γ) are also discussed.
N. K. Gaur Archana Srivastava Jyotsana Galgale
Department of Physics Barkatullah University Bhopal, India, 462026 Department of Physics Sri Sathya Sai College for Women Bhopal, India, 462024
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
706-713
2010-10-19（万方平台首次上网日期，不代表论文的发表时间）