Exchange Integral in Ni and Its Alloy Film from Spin Wave Resonance

Abstract

The excitation of spin wave resonance is investigated for various Ni films. The observation is possible only in the case of film prepared on the unheated glass substrate. It is sensitive to the inner crystalline structure of film. The exchange coupling constant A in Ni film is estimated to be 0.75×10⁻⁶ erg/cm and the exchange integral J to be 9.4×10⁻¹⁴ erg. Similarly Pd- and Cu-Ni alloy films are prepared. Their concentrations are determined. They are confirmed to have the nearly perfect structure by means of the electron diffraction. With increasing concentration of Pd and Cu, the value of A decreases monotonously to as small as about 2/3 at 35% Pd and 1/5 at 22% Cu respectively. The exchange integrals of these alloys are, however, nearly constant. The temperature variations of A and J are investigated for some Cu-Ni alloy films. The values of J are also invariant up to the Curie point.