Domain structure of micro-patterned CoZrTa with 45 degree induced anisotropy for isotropic high permeability

Magnetic materials have been utilized to increase the inductance of integrated inductors by taking advantage of their high-permeability [1]-[3]. It has been shown by simulation of the magnetic flux in a closed-core inductor that magnetic films with isotropic permeability are promising. Utilizing a core with uniaxial magnetic hard axis inevitably produces an effective air-gap, which inefficiently closes the flux loop [4]. In order to obtain isotropic permeability in both longitudinal and transverse directions of a magnetic film, a CoZrTa film was deposited with induced easy axis at a 45° angle from the conventional pattern axis. This paper studies the magnetic properties of this CoZrTa film and the domain structures of both patterned and unpatterned samples to obtain a physical understanding of the magnetization process which determines the permeability frequency spectrum.