Annealing behavior of electroplated permalloy thin films

Abstract

The isochronal annealing behavior of electroplated 1.2 μm Ni-Fe thin films containing nominally 80 wt% Ni, in the temperature range from 373° to 773°K, and with a magnetic field parallel to the easy axis of the films, was investigated through measurements of the films' structural, magnetic and electrical properties. The effects of annealing could be described in terms of two annealing stages. In stage I, occurring up to about 575°K, recovery took place along with some pairordering, resulting in small decreases in the coercivity, the easy axis dispersion and the electrical resistivity; the apparent anisotropy field increased in this stage. The stage II of annealing, occurring above 575°K, was characterized by more defect annealing, a change in the texture and possibly some long-range ordering. This stage resulted in increases in the coercivity and the dispersion, along with decreases in the apparent anisotropy field, the apparent strain sensitivity and the relative permeability. The results of both annealing stages are discussed in terms of the structural changes. © 1973 American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.