Electron-spin-resonance line broadening around the magnetic phase transition in manganites

Abstract

We report magnetization and electron-spin-resonance (ESR) measurements around the Curie temperature on single-crystal and ceramic colossal magnetoresistance manganites. The temperature dependence of the ESR linewidth below $\ensuremath{\approx}{1.1T}_{C}$ is well described in terms of a two-magnon scattering relaxation mechanism induced by the demagnetization fields of the pores between crystallites.