Magnetic materials for integrated cores

Magnetic materials for an integrated magnetic core memory have been developed. The materials are for a storage layer about 1 μm thick and a low reluctance keeper layer. Materials investigated were Co-Ni-Fe for the storage layer and Cr-Ni-Fe for the keeper. Measurements were made of
H_{c}, B_{s}, B_{r}, \lambda_{s}, S_{w}, H_{0}
, and H
disturb
. Layer stress and adhesion were also measured. Special apparatus, which is described, has been developed to perform some of the measurements. Variation of properties with substrate surface, substrate temperature, and oxygen pressure during evaporation are reported.