A new soft X-ray magnetic circular dichroism facility at the BSRF beamline 4B7B

TL;DR

This paper introduces a new soft X-ray magnetic circular dichroism (XMCD) facility at BSRF that combines ultra-high-vacuum, moderate magnetic fields, and in-situ sample prep to enhance material property studies.

Contribution

It presents the design, development, and validation of a novel XMCD apparatus with a specialized electromagnet and in-situ capabilities at BSRF.

Findings

Electromagnet performance matches simulations.

Magnetic moments of Fe and Co films agree with theoretical predictions.

Facility enables detailed element-specific magnetic studies.

Abstract

X-ray magnetic circular dichroism (XMCD) has become an important and powerful tool because it allows the study of material properties in combination with elemental specificity, chemical state specificity, and magnetic specificity. A new soft X-ray magnetic circular dichroism apparatus has been developed at the Beijing Synchrotron Radiation Facility (BSRF). The apparatus combines three experimental conditions: ultra-high-vacuum environment, moderate magnetic fields and in-situ sample preparation to measure the absorption signal. We designed a C type dipole electromagnet that provides magnetic fields up to 0.5T in parallel (or anti-parallel) direction relative to the incoming X-ray beam. The performances of the electromagnet are measured and the results show good agreement with the simulation ones. Following film grown in situ by evaporation methods, XMCD measurements are performed. Combined polarization corrections, the magnetic moments of the Fe and Co films determined by sum rules are consistent with other theoretical predictions and experimental measurements.