Electrical and thermal properties of the manganite La0.8Ag0.15MnO3.

A comprehensive investigation of the electro- and thermophysical properties of the manganite La_0.8Ag_0.15MnO₃ is carried out over a wide temperature interval (4.2–350 K) and in magnetic fields up to 26 kOe. It is shown that the colossal magnetoresistance in a magnetic field of 11 kOe amounts to 57%, and the effect is maximum at room temperature. The dominant mechanisms of current carrier scattering in the ferromagnetic and paramagnetic phases are established. An analysis of the data on the low-temperature heat capacity provides estimates of the electronic density of states at the Fermi level, N_F=6.82×10²⁴ eV^-1 mol^-1, and of the Debye temperature, θ_D=370 K. The results of thermal expansion measurements are used to find the spontaneous magnetostriction. It is found that the phonon mechanism of heat transfer is dominant, and the local Jahn–Teller distortions are considered as the main mechanism of phonon scattering. [ABSTRACT FROM AUTHOR]