Detection of Multilayer Nano Structures by One Directional Polarization Analysis in Neutron Reflectometry

Submitted: Jul 16, 2013; Accepted: Aug 25, 2013; Published: Aug 29, 2013 Abstract: Due to the sensibility of neutron spin to the intrinsic magnetic field of magnetic materials, polarized neutron reflectometry is widely used in investigation of magnetic properties of nano-structures. Type and thickness of a multilayer can precisely be determined by measuring the polarization of reflected neutrons from the sample. In the past decades, several theoretical methods have been worked out to determine the type and thickness of thin films as a function of scattering length density (SLD) of the sample based on polarization analysis. However, as the technology of available reflectometers is limited in a way that the polarization of the reflected neutrons can be measured in the same direction as the polarization of the incident neutrons, these methods have to be modified by considering this limitation. In this paper, we have proposed a method for determining the SLD of a multilayer based on using a magnetic substrate and polarization measurement of reflected neutrons in the same direction as the polarization of incident beam. Our method, resolves this problem for available neutron reflectometers.