Electron paramagnetic resonance investigation of the electron-doped manganite La1−xTexMnO3 (0.1 ≤x≤0.2)

Abstract

The electron paramagnetic resonance (EPR) properties of the electron-doped manganite La(1-x)Te(x)MnO(3) (0.1 ≤ x ≤ 0.2) are investigated based on the data of EPR spectra, resistivity, and magnetic susceptibility. With decreasing temperature from 400 K, the EPR linewidth ΔH(PP) decreases and passes through a minimum at T(min), then substantially increases with further decreasing temperature. The broadening of the EPR linewidth above T(min) can be understood in terms of the increase in the relaxation rate of spin of e(g) polarons to the lattice with increasing temperature due to the similarity between the temperature dependence of the linewidth ΔH(pp)(T) and the conductivity σ(T). For the samples with x = 0.1 and 0.15, the conductivity activation energy E(σ) is comparable with the activation energy E(a) deduced from the linewidth. Whereas for the x = 0.2 sample, there is a large difference between E(σ) (0.2206 eV) and E(a) (0.0874 eV).