Magnetic Analysis of Nickel Films Deposited by Evaporation

The magnetic properties of nickel films deposited from vapor on surfaces at several temperatures and, in some cases, annealed to various degrees have been studied at room temperature. Films deposited at room temperature are magnetically hard, having low initial susceptibility (${\chi }_0$). For films deposited on a metal with a higher coefficient of linear expansion than nickel, raising the temperature of deposition or annealing at higher temperatures increases ${\chi }_0$. For films on a metal with a lower coefficient of linear expansion than nickel ${\chi }_0$ first increases with deposition or annealing temperature but decreases upon high temperature annealing. The results are explained on Becker's theory by assuming that the films are deposited under strain, these deposition strains becoming less at higher temperatures.