Pressure effects on the charge and spin states and the relation between the ferromagnetic and metallic states were explored on the small bandwidth manganite Pr1-xCaxMnO3 (x=0.25, 0.3, 0.35). Under pressure, the charge ordering state is suppressed and a ferromagnetic metallic state is induced in all three samples. The metal-insulator transition temperature (TMI) increases with pressure below a critical point P*, above which (TMI) decreases and the material becomes insulating as at the ambient pressure. The eg electron bandwidth and/or band filling mediate the pressure effects on the metal-insulator transition and the magnetic transition. In the small bandwidth and low doping concentration compound (x=0.25), the TMI and the Curie temperature (TC) change with pressure in a reverse way and do not couple under pressure. In the x=0.3 compound, the relation of TMI and T C shows a critical behavior: They are coupled in the range of ∼0.8-5 GPa and decoupled-outside of this range. In the x=0.35 compound, TMI and TC are coupled in the measured pressure range where a ferromagnetic state is present.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Sep 2004|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics