Effect of grain size on intergranular magnetostatic coupling in thin-film media

In order to characterize the intergranular coupling and to clarify the effect of grain size on intergranular magnetostatic coupling in thin-film media, the temperature dependences of magnetic properties Hc, Hkgrain, and Ms for ultraclean-(UC)-processed CoCrTa media with various grain sizes have been examined in order to discuss the effect of grain size on intergranular magnetostatic coupling. The results are that (1) in the UC-processed media, the magnetostatic coupling mode is found to be dominant as the intergranular coupling and in the normal processed media, the exchange coupling mode is dominant, and (2) the decrease in 4πMs/Hkgrain below 1.0 is the most effective to suppress the increment in the magnetostatic coupling due to the reduction in the grain size, were clarified.