J. Baszyński

Electronic structure of La0.65Pb0.35MnO3 perovskite studied by X-ray photoemission spectroscopy

Abstract The electronic structure of La 0.65 Pb 0.35 MnO 3 has been studied by X-ray photoemission spectroscopy (XPS). The valence band spectrum is compared with ab-initio electronic structure calculations using linearized muffin–tin orbital (LMTO) method. The XPS measurements, and the theoretical band-structure calculations for La 0.75 Pb 0.25 MnO 3 , show that the electronic structure of La 0.65 Pb 0.35 MnO 3 compound consists mainly of Mn 3d and O 2p states. In addition, the Mn 3d and O 2p states are hybridized over the whole valence band. States of 3d characters localized in Mn site predominate near the top of the valence band. We have found a good agreement between the experimental valence band spectra and theoretical calculations.

Electronic structure of doped LaMnO3 perovskite studied by x-ray photoemission spectroscopy

The electronic structure of La2/3Sr1/6Pb1/6MnO3 has been studied by x-ray photoemission spectroscopy (XPS). The valence band spectrum is compared with ab initio electronic structure calculations using a linearized muffin-tin orbital (LMTO) method. The XPS measurements and the theoretical band structure calculations for La1/2Sr1/4Pb1/4MnO3 show that the electronic structure consists mainly of Mn(3d) and O(2p) states. In addition, the Mn(3d) and O(2p) states are hybridized over the whole valence band. States of 3d character localized on Mn sites predominate near the top of the valence band. It was found that the doping, both with the Pb and the Sr ions, increases the spin polarization by up to 48%.

Magnetic and transport properties of Tm2Co7B3 compound

Magnetic and transport properties of Tm2Co7B3 compound have been studied. This compound crystallizes in the hexagonal Ce2Co7B3 type structure. The coercivity (Hc) of the compound was determined from hysteresis measurements in fields up to 4 T. The temperature dependence of coercivity has been explained by a thermally activated process of domain wall motion. The resistivity at low temperatures shows a T2 dependence. At higher temperatures the resistivity is not a linear function of temperature, which indicates an electron-phonon interaction in the presence of a small s-d scattering.