Magnetically correlated internal friction and Young’s modulus in La(Y)-Ca-Mn-O perovskites

Abstract

Internal friction ${(Q}^{\ensuremath{-}1})$ and Young's modulus have been studied on a series of ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}$ and ${\mathrm{La}}_{0.6}{\mathrm{Y}}_{0.07}{\mathrm{Ca}}_{0.33}{\mathrm{MnO}}_{3\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}$ polycrystals. A ${Q}^{\ensuremath{-}1}$ peak originating from the changes of the magnetic entropy is observed. The ${Q}^{\ensuremath{-}1}$ peak for $x$ in the range of $0<x<0.5$ can be correlated with a transition from a paramagnetic (PM) disordered state to a ferromagnetic (FM) ordered state accompanied by a cooperative Jahn-Teller lattice distortion; from a PM insulator to a spin-glass insulator and accompanied with a large loss of modulus for $0.5<x<1.0;$ and the ${Q}^{\ensuremath{-}1}$ peak is ascribed to a transition from a PM to an AFM insulator for $x=1.0.$