Modifying interlayer coupling in CoFe/Bi/Co trilayer junction by post-annealing treatments

Trilayer structures CoFe/Bi/Co were prepared by dc sputtering at room temperature. The samples were then annealed at temperatures from 50/spl deg/C to 250/spl deg/C for 30 minutes. The crystalline structure, microstructures and magnetization loops of the as-deposited and annealed samples were investigated by X-ray diffraction, transmission electron microscopy (TEM) and vibrating sample magnetometer respectively. The correlation of interface parameters with interlayer coupling was analyzed and presented as function of the different annealing temperatures.