Reactively sputtered epitaxial γ′-Fe4N films: Surface morphology, microstructure, magnetic and electrical transport properties

Abstract

Epitaxial γ′-Fe4N films with (100) and (110) orientations have been fabricated by reactive sputtering; these films were characterized by X-ray θ–2θ and φ scans, pole figures and high-resolution transmission electron microscopy. The film surface is very smooth as the film is less than 58nm thick. The films exhibit soft ferromagnetism, and the saturation magnetization decreases with an increase in temperature, following Bloch’s spin wave theory. The films also exhibit a metallic conductance mechanism. Below 30K, magnetoresistance (MR) is positive and increases linearly with the applied field in the high-field range. In the low-field range, MR increases abruptly. Above 30K, MR is negative, and its value increases linearly with the applied field.