Structural characterization of giant magnetoresistance multilayers with new grazing incidence x-ray fluorescence

We have developed a grazing incidence x-ray fluorescence (GIXRF) technique based on wavelength dispersive (WD) fluorescence equipment with high-brilliance synchrotron radiation x-rays at SPring-8. The technique has been successfully applied to the evaluation of the stratified structure of giant magnetoresistance (GMR) multilayers. Because of the good energy resolution and high count rate of the WD detector, high-quality data about the dependence of fluorescence intensities on the incident angle for the composition elements were obtained. An analysis program based on matrix formalism has been developed, and a good agreement between data and model calculations has been obtained. The results indicate that excessive thermal treatment causes a roughening of inter-layer interfaces, which degrades the magnetic properties of a GMR head.