Phase separation in La0.5Ca0.5MnO3 observed by Mn-55 and La-139 NMR

Abstract

We studied zero-field Mn-55 and La-139 nuclear magnetic resonance (NMR) in La0.5Ca0.5MnO3. The Mn-55 and La-139 NMR intensities, resonance frequencies, and spin-spin relaxation times showed thermal hystereses upon cooling and warming. The analysis of the result shows that there are two distinct phase regions below T-C: a stable metallic ferromagnetic (FM) region and a region where metallic FM and insulating antiferromagnetic phases compete. The two metallic FM phases are distinguished by mobile e(g) electron density. The e(g) electron density of the stable FM phase is 0.5, but that of the FM phase:in the competition region is lower than that. [S0163-1829(99)04945-0].