Specific heat and transport properties of La 1− xGd xMnO 3 at [formula omitted

Abstract

We have investigated the specific heat and transport properties of the doped perovskite manganites La 1− x Gd x MnO 3 with 0.0 ≤ x ≤ 1.0 in the temperature range 15 K ≤ T ≤ 300 K using the Modified Rigid Ion Model (MRIM), probably, for the first time. At room temperature, for all doping levels the orthorhombic ‘O’ phase is indicative of a strong Jahn–Teller distortion. Our theoretical results on the specific heat for La 1− x Gd x MnO 3 ( x = 0.0 , 0.75 and 1.0) as a function of temperature 15 K ≤ T ≤ 300 K are closer to the available experimental data with minor deviations at lower and higher temperatures. The MRIM results have predicted the observed anomalies for x = 0.0 , 0.75, 1.0 in the temperature range 30 K ≤ T ≤ 126 K and revealed new anomalies for x = 0.25 and 0.50 in the temperature range 50 K ≤ T ≤ 100 K . Further, we have computed the temperature and composition ( x ) dependence of the transport properties, like the cohesive energy ( ϕ ) , Restrahalen frequency ( υ 0 ) , Debye temperature ( θ D ) and Grüneisen parameter ( γ ) and compared them with the experimental data available only at room temperature (300 K) for the concentrations x = 0.0 and 1.0.