Photoemission electron microscopy for the study of ferromagnetic and antiferromagnetic materials

Abstract

Photoemission electron microscopy (PEEM) is a full field imaging technique where x-ray exited electrons are used to form an image of the sample surface as a function of the x-ray photon energy and polarization. Contrast in PEEM can be due to a number of mechanisms including topographical, work function, elemental, chemical, polarization, x-ray magnetic circular and linear dichroism contrast. This wide range of contrast mechanisms together with the surface sensitivity and high spatial resolution make PEEM a very useful tool for the study of magnetic materials. PEEM-II is a new microscope installed at the bending magnet beamline 7.3.1.1 of the Advanced Light Source. In the present paper we describe the design and features of PEEM-II, and show results of our recent studies. Using PEEM and its elemental specificity, it is possible to investigate the various layers in magnetic multilayer structures independently. The experiments described here include the investigation of the switching behavior of magnetic multilayer structures that are of interest for magnetic RAM applications. The study of antiferromagnetic surfaces and thin films are of great importance for devices based on the effect of exchange bias. To date, studies at high-spatial-resolution of exchange bias systems has been difficult because of the lack of appropriate investigation methods. Here we demonstrate how PEEM has been used to image antiferromagnetic structure on surfaces with high spatial resolution.