Stripe and cylindrical domains in amorphous Co-P and Co-Ni-P films

Amorphous electrodeposited Co-P and Co-Ni-P films (∼24 at.% P,≤ 26 at.% Ni) are ferromagnetic and have perpendicular easy-axis anisotropy, with anisotropy fields Hk= 2K/Mssmaller than 4πMs. Stripe and bubble-like, cylindrical domains have been observed in some of these films by Bitter techniques. Thickness dependence of the in-plane saturation field agrees with Murayama´s [J. Phys. Soc. Japan 21, 2253 (1966)] micromagnetic calculation. The zero field stripe period is that expected for a parallel plate domain structure with flux closure.