Spin-Wave Excitation Dependence upon Oxygen in Thin Nickel-Iron Layers

Abstract

A clear‐cut characterization of the role of oxygen present in 83 Ni–Fe vapor‐deposited thin layers has been sought by a series of spin‐wave resonance experiments upon samples that have been prepared under controlled ultrahigh vacuum conditions. Dryed oxygen was leaked into the vacuum chamber to obtain partial pressures of 1 and 5×10⁻⁸ and 1×10⁻⁷ Torr, prior to the formation of and during the cooling of the UHV condensed films. Of significance has been the response of the main peak resonance field strength, linewidth and intensity to the oxygen vapor point relative to a best vacuum, minimum oxygen, fabrication condition (−9 Torr). With an increase of oxygen the resonance field strength and intensity decrease and the linewidth increases. A direct influence of oxygen is observed to begin by extrapolation at 10⁻⁹ Torr partial pressure. Resonance line spacings were invariant to the controlled oxygen vapors. From the results that have been obtained, it can be surmised that the bulk magnetic properties of these thin layers are altered magnetically only slightly for oxygen content less than 10⁻⁸ Torr, and as the oxygen content increases, (1) it decreases the average magnetic moment of the layer through the formation of oxides; (2) a structural linewidth mechanism has been introduced; and (3) the basic spin‐constraint mechanisms have not been altered.