The nature of metal-insulator (MI) transition in a t2g-electron system Ca2-xSrxRuO4 has been investigated using O 1s x-ray absorption spectroscopy (XAS). The O 1s XAS data strongly depend on temperature and demonstrate that the hysteresis of the MI transition is accompanied by the hysteresis of the orbital change. An unrestricted Hartree-Fock analysis indicates that the amount of yz/zx hole is discontinuously reduced at the MI transition. In the insulating phase, the amount of 4d yz/zx hole gradually decreases on heating, suggesting that partial orbital fluctuation increases with temperature.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2004 Apr 1|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics