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Temperature dependence of the electronic structure of the charge-ordering manganite Pr 0.5 Sr 0.5 <mml:mi mathvariant="…

1997; American Physical Society; Volume: 56; Issue: 24 Linguagem: Inglês

10.1103/physrevb.56.r15513

1095-3795

A. Chainani, Hiroshi Kumigashira, T. Takahashi, Y. Tomioka, H. Kuwahara, Y. Tokura,

Electronic and Structural Properties of Oxides

We study the changes in the occupied density of states of ${\mathrm{Pr}}_{0.5}{\mathrm{Sr}}_{0.5}{\mathrm{MnO}}_{3}$ as a function of temperature (25--300 K) using photoemission spectroscopy. The spectral weight transfer across the metal-insulator/charge-ordering/ferromagnetic-antiferromagnetic transition is abrupt and over very large energy scales (up to 1.2 eV from the Fermi level ${E}_{F})$ compared to the transition temperature ${T}_{\mathrm{mi}}=140 \mathrm{K}$ (\ensuremath{\sim}12 meV) and the gap value in the insulating phase (\ensuremath{\sim}100 meV). Negligible changes observed at ${E}_{F}$ in the ferromagnetic-metallic phase above ${T}_{\mathrm{mi}}$ and a weak spectral weight transfer across the ferromagnetic-paramagnetic transition at ${T}_{\mathrm{fp}}=270 \mathrm{K}$ are consistent with negligible change in carrier density above ${T}_{\mathrm{mi}}.$