Magnetization and electronic structure of polycrystalline La1-xCax MnO3(x=0.19, 0.17)

Magnetization and electronic states of polycrystalline La1-xCax MnO3 (LCMO, x=0.19, 0.17) were studied in order to further understand the nature of Griffiths phase in LCMO. The results of hysteresis loop and X-ray photoemission spectroscopy (XPS) spectra of Mn 2p demonstrated the intrinsic inhomogeneity and competition between coexisted phases of paramagnetic phase and ferromagnetic phase caused by mixed valence states of Mn3+ and Mn4+. The valence band spectra (VBS) of samples indicated that there is high degree of hybridization of egstates and O 2p orbital. Combined with the local structure change of crystal lattice, the higher degree of hybridization of these orbitals may play an important part on the physical properties, like Griffiths phase, in prepared samples. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)