CATIONIC DISTRIBUTION IN RELATION TO THE MAGNETIC-PROPERTIES OF NEW M-HEXAFERRITES WITH PLANAR MAGNETIC-ANISOTROPY BAFE(12-2X)IR(X)ME(X)O(19) (ME=CO,ZN, X-APPROXIMATE-TO-0.85 AND X-APPROXIMATE-TO-0.50)

Single crystals of BaFe(12-2x)Ir(x)Me(x)O(19) with Me = Co, Zn and 0 l ess than or equal to x less than or equal to 1 have been prepared by a flux method. Precise crystal structures of substituted compounds (Ir- Co with x = 0.85 and Ir-Zn with x = 0.50) have been determined by usin g a four-circle diffractometer, and cation distribution on all crystal lographic sites has been refined. Magnetization measurements have been performed on single crystals at room and liquid helium temperatures. Observed magnetic anisotropy is planar, and saturation magnetizations are in good agreement with the cation distributions determined by X-ra y diffraction. Magnetic anisotropy change is correlated with the subst itutions of Ir for Fe cations on bipyramidal and octahedral sites of t he R block, and Me for Fe cations on tetrahedral and bipyramidal sites . (C) 1995 Academic Press, Inc.