Polarized neutron channeling in weakly magnetic films

TL;DR

This paper introduces a novel polarized neutron channeling technique for highly sensitive detection of weak magnetization in thin films, utilizing neutron tunneling and polarization analysis within a waveguide setup.

Contribution

The study presents a new method for detecting extremely small magnetizations in weakly magnetic films using polarized neutron channeling, enhancing sensitivity over existing techniques.

Findings

Successfully detected magnetization as low as a few 10 Gauss.

Demonstrated the method on a Tb-containing magnetic film.

Provided experimental validation with polarized neutron reflectometry.

Abstract

We describe a new sensitive method for the investigation of weakly magnetic films placed inside a tri-layer planar waveguide. Polarized neutrons tunnel into the waveguide through the surface, channel along the layers and are emitted from the end face as a narrow and slightly divergent microbeam. Polarization analysis permits to detect very small magnetization in the order of a few 10 Gauss. The magnetic film containing the rare-earth element Tb was investigated using both fixed wavelength and time-of-flight polarized neutron reflectometers. The experimental results are presented and discussed.