Characteristic Phonon Scattering Enhancement Correlated with Magnetic and Charge Orders in La1?XSrXMnO3 (X ? 0.50)

Abstract

The thermal conductivity κ(T) and the thermal diffusivity α(T) of La1—XSrXMnO3 (X ≥ 0.50) have been measured and phonon scattering mechanisms have been analyzed in terms of the power of dependence on phonon frequency ωph. For 0.50 ≤X < 0.55, where the high temperature ferromagnetic phase becomes unstable against the A-type antiferromagnetic (AF) order, the phonon scattering mechanism proportional to ω1ph is enhanced in the low temperature AF phase. In contrast, in the charge ordered phase for X ≥ 0.67, the phonon scattering mechanism proportional to ω4ph is enhanced. The enhancement in the phonon scattering mechanisms reflects the types of the order in this manganese system.