부산대학교 도서관

Magnetization hysteresis loops, dc and ac magnetic susceptibilities, and Raman vibrations have been characterized in (BiBa)FeO ceramics for x = 0.0, 0.05, 0.10, and 0.15 as functions of temperature. Ferromagnetic hysteresis loops were observed in Ba-doped compounds with increasing magnetization as Ba substitution increases. High-resolution synchrotron Fe K- and L -edge X-ray absorptions reveal an Fe valence and a modification of the Fe-O-Fe bond structure by the A-site Ba substitution. The oxygen K-edge X-ray absorption suggests that the hybridization of the O 2 p and Fe 3 d orbitals was reduced by the Ba substitution. Field-cooled and zero-field-cooled magnetic susceptibilities reveal a spin-glass behavior, which was enhanced with increasing Ba substitution. Raman vibrations of the Bi- and Fe-sensitive E(2) and A (1) modes reveal frequency softening and step-like anomalies in full-width-at-half-maximum in the vicinity of ~150-250 K, which were attributed to spin-phonon interaction while magnetic ordering transitions take place. [ABSTRACT FROM AUTHOR]