Abstract
Magnetic properties of BaFe12-(x+y)SnxCoyO19 single crystals, with 0 less than or equal to x less than or equal to 2 and 0 less than or equal to y less than or equal to 2, have been investigated in the temperature range 6 to 320 K with a varying field from -5 to +5 T applied parallel and perpendicular to the c-axis. It is found that when Fe3+ is substituted by Co2+ and Sn2+, the anisotropy and saturation magnetization of these materials are reduced. With x + y < 1.5, the sample exhibits long range magnetic ordering with the uniaxial anisotropy in the c-axis. When the substitution was increased to x + y = 2.5, the long distance magnetic coupling is partially destroyed, and the sample behaves as a weakly long-range anisotropy granular material. At x + y similar to 4, the sample shows reentrant spin glass behavior.