Structural, dielectric and magnetic properties of Ba3SrLn2Fe2Nb8O30 (Ln = La, Nd, Sm) filled tungsten bronze ceramics

Structural, dielectric and magnetic properties have been investigated for Ba3SrLn2Fe2Nb8O30 (Ln = La, Nd, Sm) ceramics. The single phase tetragonal filled tungsten bronze structure in space group P4/mbm is obtained for Ba3SrLa2Fe2Nb8O30, while such tungsten bronze major phase is determined together with minor amount of secondary phases in Ba3SrNd2Fe2Nb8O30 and Ba3SrSm2Fe2Nb8O30. The saturated magnetic hysteresis loops with enhanced Mr are obtained in the present ceramics at room temperature comparing to the Ba4Ln2Fe2Nb8O30 (Ln = La, Nd, Sm) ceramics. Meanwhile, the typical relaxor behaviors are determined: a broad dielectric peak with strong frequency dispersion and the peak temperature following well with the Vogel-Fulcher relationship.