Spin-sensitive magnetic microscopy with circularly polarized X-rays

X-ray dichroism microscopy is a new method for microscopic mapping of magnetic domains at surfaces, that measures the local magnetic moment and magnetization direction of individual elemental constituents of the sample. In addition, it is able to probe the magnetic properties of layers buried as much as 100Å below the surface. The method uses the magnetic X-ray dichroism effect, in combination with the X-ray photoelectron emission microscope (X-PEEM), also called the X-ray secondary electron microscope (XSEM). The X-PEEM has already been shown to be a valuable tool for small-area X-ray absorption fine-structure (XAFS) spectroscopy, and for state-selected imaging. In this paper, the principles involved in imaging magnetic domains using the X-ray photoelectron emission microscope are discussed, based on recent results with circularly polarized soft X-rays. Examples of applications of the technique are reviewed, including direct mapping of the oscillatory exchange coupling in transition metal sandwich structures, and imaging of recorded bit patterns in magnetic media

Soft x-ray spectromicroscopy development for materials science at the Advanced Light Source

Several third generation synchrotron radiation facilities are now operational and the high brightness of these photon sources offers new opportunities for x-ray microscopy. Well developed synchrotron radiation spectroscopy techniques are being applied in new instruments capable of imaging the surface of a material with a spatial resolution smaller than one micron. There are two aspects to this. One is to further the field of surface science by exploring the effects of spatial variations across a surface on a scale not previously accessible to x-ray measurements. The other is to open up new analytical techniques in materials science using x-rays, on a spatial scale comparable to that of the processes or devices to be studied. The development of the spectromicroscopy program at the Advanced Light Source will employ a variety of instruments, some are already operational. Their development and use will be discussed, and recent results will be presented to illustrate their capabilities