Peculiar behavior of the initial magnetization in CoNi thin films

Abstract

The initial magnetization curve of ac demagnetized CoNi thin films were outside the hyteresis loop boundary before saturation. Using −dc demagnetization, the initial magnetization curve was brought into the hysteresis loop boundary. Henkel plot shows negative deviation in ac demagnetized CoNi thin film, and both positive and negative deviation, in −dc demagnetized CoNi film. Bitter domain imaging technique showed that the initial magnetization effects are due to the corresponding domain configurations obtained in ac and in −dc demagnetization.