Anomalous Jahn-Teller distortions in La0.75Ca0.25MnO3 system: An X-ray absorption study.

Mn K-edge X-ray absorption near edge structure (XANES) measurements have been made to study the temperature-dependent lattice effects in the La_0.75Ca_0.25MnO₃ system. The high-resolution XANES spectra recorded with high signal-to-noise ratio have allowed us to study the temperature dependence of the Jahn-Teller splitting indicated directly by the dipole forbidden pre-peaks corresponding to transition in Mn 3 d states. The results show splitting of the e _g state in its two orbitals ( d <subscript />x² -_y ² and d _3z ²-_r ². The energy splitting shows anomalous temperature dependence across the giant magnetoresistance transition temperature. [ABSTRACT FROM AUTHOR]