Polarized neutron reflectometry: recent developments and perspectives

Abstract

Polarized neutron reflectometry (PNR) has an important role in solving non-collinear magnetic structures in thin films. In principle PNR provides the unambiguous determination of multi-axial magnetic depth profiles in systems of scientific and technological importance. However, only a limited number of problems have been solved unimpeachably, because the magnetic depth profiles were obtained by fitting procedures yielding solutions whose main features were not evident in the raw data. A recent formulation of reflectometry, and the concurrent development of “total polarimetry” are now stimulating the design of neutron polarization and polarization analysis geometries capable of determining directly if and how a magnetic system contains a non-collinear structure in the film ( x– y) plane. In the simplest of these geometries the neutrons are polarized and analyzed along the z-axis perpendicular to the film plane.