Exploring nanoscale magnetism in advanced materials with polarized X-rays

Nanoscale magnetism is of paramount scientific interest and high technological relevance. To control magnetization on a nanoscale, both external magnetic fields and spin polarized currents, which generate a spin torque onto the local spin configuration, are being used. Novel ideas of manipulating the spins by electric fields or photons are emerging and benefit from advances in nano-preparation techniques of complex magnetic materials, such as multiferroics, ferromagnetic semiconductors, nanostructures, etc.Advanced analytical tools are needed for their characterization. Polarized soft X-rays using X-ray dichroism effects are used in a variety of spectroscopic and microscopic techniques capable of quantifying in an element, valence and site-sensitive way basic properties of ferro(i)- and antiferromagnetic systems, such as spin and orbital moments, nanoscale spin configurations and spin dynamics with sub-ns time resolution. Future X-ray sources, such as free electron lasers will provide an enormous increase in peak brilliance and open the fs time window to studies of magnetic materials. Thus fundamental magnetic time scales with nanometer spatial resolution can be addressed.This review provides an overview and future opportunities of analytical tools using polarized X-rays by selected examples of current research with advanced magnetic materials.