Dependence of Magnetic Properties of Fe/Al Multilayers on Layer Thickness and Temperature

Magnetic properties of Fe/Al multilayer structures are studied as a function of thickness and temperature using vibrating sample magnetometer (VSM). The XRD measurements show substantial interdiffusion at the interfaces, and particularly at lower thicknesses, these multilayer structures look like a composite single layer film of Fe and Al. The corresponding magnetic measurements show a soft magnetic behaviour of all the films with an in-plane easy direction of the magnetization. However, at low temperature, 100 K, both coercivity and saturation field increases as compared to room temperature below dFe ≤ 20 Å and is probably due to the existence of antiferromagnetic interlayer coupling between the iron layers, which coexist with the ferromagnetic interaction within each iron layer and also due to alloying at the interfaces.