Bulk-sensitive magnetic microscope utilizing x-ray magnetic circularly polarized emission

Abstract

We report a bulk-sensitive x-ray magnetic microscope that exploits a new magneto-optical effect in x-ray emission, referred to as x-ray magnetic circularly polarized emission (XMCPE). An advantage of XMCPE is a large magnetic dichroic effect for 3d transition-metal elements in the hard x-ray region, which enables the realization of a bulk-sensitive microscope suited to iron- and cobalt-rich ferromagnetic materials. We constructed a scanning microscope with 10 μm lateral resolution. A key element is a Montel-type collimating mirror that widely collects the divergent x rays emitted from a sample and converts them into a well-collimated x-ray beam, which is required for circular polarization analysis. Owing to this mirror, the obtained XMCPE spectra of metallic iron exhibited strong intensity and a large magnetic dichroic effect. The performance of the microscope is also demonstrated by the acquisition of magnetization images of an electrical steel sheet with an insulating coating.

Observation of Buried Magnetic Domains in Grain-Oriented Electrical Steel

“…4(a) in Ref. [26]), whereas the observed width is approximately 120 µm. Therefore, it is probable that two or more lancet domains joined to afford the observed large lancet domain.…”

“…The details of the XMCPE microscope are presented in Ref. [26]. We obtained magnetic domain images at three pairs of θ in and θ ex values, namely, 90 • and 70 • , 70 • and 90 • , and 50 • and 110 • , respectively.…”

“…Very recently, we developed a new bulk-sensitive magnetic microscopy technique that utilizes a new magneto-optical effect in the X-ray region, which we refer to as X-ray magnetic circularly polarized emission (XMCPE) [26]. At present, a lateral resolution down to 10 µm has been achieved and a probing depth of up to 40 µm is expected.…”