CFN/NSLS Joint Seminar

By using a transmission x-ray microscope with precision zone plate optics, imaging can be achieved with a demonstrated spatial resolution finer than 25 nm. Image contrast can be obtained with x-ray magnetic circular dichroism, allowing direct imaging of the element-specific orientation of the magnetization within samples. Experiments have been performed using the XM-1 x-ray microscope at the Advanced Light Source which can use x-rays between 300 and 1800 eV allowing element-specific magnetic imaging for various elements including Fe, Co, Ni, and Gd. The ability to magnetically characterize samples with 25 nm resolution gives a deeper understanding of magnetic properties and paves the way for future progress in such technically relevant fields as high-density magnetic storage in hard disk drives. Recent experiments include analyzing aligned images of both magnetization and crystal structure to probe the complicated relationship between the two in magnetic materials. Additionally, recent research has exploited the element-specific magnetic contrast to measure the magnetization of each layer in a bi-layer system, which is the likely design for perpendicular magnetic recording devices. While the current emphasis of experimentation with the microscope is on understanding magnetic properties on the nanometer scale, a brief synopsis will also be given of other recent high resolution imaging studies of electromigration in passivated interconnects, high-resolution tomography of biological samples, and mask inspection for extreme ultraviolet lithography.