Thermal expansion of Ti-substituted barium hexaferrite

Thermal expansion measurements in the range of 20-500 degrees C were carrie d out on both poly- and single crystalline samples of the hexagonal magneto plumbite ferrite with composition BaTiFe11O19. The continuous scanning of t he thermal expansion reveals the existence of a lambda-type anomaly near th e Curie temperature. In contrast to the usual observed anisotropic behavior for magnetoplumbite hexaferrites, the averaged thermal expansion coefficie nt for the a direction is larger than for the c direction, i.e., 12.8x10(-6 ) and 9.5x10(-6) degrees C-1, respectively. (C) 2000 American Institute of Physics. [S0021-8979(00)00107-9].