Gao Guo-Mian

Anomalous specific heat of charge-ordered La0.5Ca0.5MnO3

An exact treatment of the double exchange-Holstein model with an electron-phonon interaction γ coupled to magnetism is used to compute the heat capacity. The model is performed combining a mean-field approximation for the double exchange interaction and the Lang–Firsov transformation for the electron-phonon interaction. The calculated results of heat capacity point to the dominance of the lattice contribution, especially in the ferromagnetic regime. This behavior is in qualitative agreement with experimental findings.

Photoinduced Resistance Change in an Oxygen-Deficient La0.9Sr0.1MnO3−δThin Film

Photoinduced resistance change (ΔR/R) in an oxygen-deficient La0.9Sr0.1MnO3−δ thin film is studied. At room temperature, the resistance change of about 30% and response time of about 75 ns are observed under the illumination with a 532 nm laser pulse of 7 ns and light power of 750 mW. It is also found that ΔR/R changes with the light power. The phenomena are explained in terms of the photoinduced hole carriers and localized insulator-to-metal transition, which may have potential applications in optoelectronic devices.