Electronic structure of the electron-doped Ca0.86Pr0.14MnO3

Abstract

We have studied the temperature-dependent changes in the near E F electronic structure of the electron-doped, phase separated colossal magnetoresistance (CMR) compound, Ca 0.86 Pr 0.14 MnO 3 using photoemission and x-ray absorption studies. At low temperatures, this compound shows a high e g electron density near the E F though the compound is insulating. Photoemission measurements further showed a temperature dependence of the e g electron occupation and localization while the complementary results of XAS showed corresponding changes in the number of unoccupied states. Our results indicate a transfer of charges from the t 2g states to the e g band, probably due to a decrease in the crystal field splitting in the ferromagnetic metallic (FMM) phase following the structural changes of the MnO 6 octahedra at low temperatures. We have interpreted our results from a FMM-antiferromagnetic insulating (AFMI) phase separation scenario.

Valence-band study of Sm0.1Ca0.9−xSrxMnO3 using high-resolution ultraviolet photoelectron spectroscopy

“…The observed features in the spectra ( Fig. 1) are the characteristics of manganites studied earlier [21][22][23][24][25][26][27][28]. However, our present focus here is to investigate the finer variations of the electronic states in the vicinity of the Fermi level.…”