Measured Relaxation Times for the Uniaxial-Anisotropy Spectrum in Nonmagnetostrictive Permalloy Films

Publisher Website
Google Scholar
Abstract
The relaxation time τ for realignment of an atomic anisotropy by 90° has been measured for a number of fast processes (τ3 sec) occurring in nonmagnetostrictive Permalloy films. The method of measurement utilizes the magnetoresistance effect and is described in detail elsewhere. For films deposited between 23° and 200°C at 10−6 to 10−5 Torr and measured at the same temperature and pressure, three distinct processes plus two probable ones have been found, which together account for about one‐quarter of the total anisotropy. The activation energy Q and period factor τ0 which determine the relaxation time τ=τ0 exp (Q/kT) have been determined for each of these processes.