Transmission X-ray microscopy using X-ray magnetic circular dichroism

X-ray magnetic circular dichroism (X-MCD) was used as a large, element-spec ific and quantitative magnetic contrast mechanism in the soft X-ray microsc opes at BESSY I (Berlin) and the ALS (Berkeley). The present state and pote ntial of magnetic transmission X-ray microscopy (MTXM) is outlined. The pos sibility to record images in varying magnetic fields and the high spatial r esolution down to 25 nm were used to image out-of-plane magnetized (4 Angst rom Fe / 4 Angstrom Gd) x 75 systems. Magnetic domains could be studied in arrays of circular and square dots with lateral dimensions down to 180 nm. Hysteresis loops of individual dots were deduced using the direct proportio nality of the X-MCD contrast to the sample magnetization. Images of a 3 nm Cr / 50 nm Fe / 6 nm Cr film demonstrate for the first time that MTXM is al so able to observe in-plane magnetized domains. In the future the possible applications of MTXM will be extended with regard to the strength of the ex ternal field, the available energy range and the sample conditions by build ing a dedicated transmission X-ray microscope for magnetic imaging at BESSY II.