The (Zn1-xCox)(2)-W type barium hexaferrite thin films have been prepared by a radio frequency magnetron sputtering method on the Si (100) and the Si (111) substrates respectively. With increasing the annealing temperatures (800, 850, 900, 950, and 1000 degrees C), the Ba(CoZn)(2)Fe16O27 phases emerge from the amorphous matrix. The hexaferrite thin films on Si (111) substrates have a larger saturation magnetic field (636.6 kA/m) than those on Si (100) substrates (159.1 kA/m). The magnetic hysteresis measurements show that they exhibit an isotropic behavior for thin films deposited on both substrates. Films on the Si (111) substrates are magnetically harder than those on the Si (100) substrates. (C) 2007 Elsevier B.V. All rights reserved.