SUBSTRATE-TEMPERATURE EFFECT ON GIANT MAGNETORESISTANCE OF SPUTTERED CO/CU MULTILAYERS

The relation between giant magnetoresistance (GMR) and the substrate temperature was investigated in sputtered Co/Cu multilayers. The magnetoresistance (MR) ratio is increased as the substrate temperature is decreased. The increase in the MR ratio is considered to be caused by the improvement in the sharpness of interfaces as concluded from the satellite peak intensity of the x-ray diffraction. The rough interfaces reduce the antiferromagnetic coupled areas and result in the MR ratio decrease. By lowering the substrate temperature to 20 degrees C, the MR ratio of 80% at room temperature was obtained.