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.

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Low-temperature specific heat of CaRu1−xMnxO3 was measured to clarify the role of d electrons in ferromagnetic and antiferromagnetic orders observed above x = 0.2. Specific heat divided by temperature Cp/T is found to roughly follow a T 2 function, and relatively large magnitudes of electronic specific heat coefficient γ were obtained in wide x range. In particular, γ is unchanged from the value at x = 0 (84 mJ/K 2 mol) in the paramagnetic state for x ≤ 0.1, but linearly reduced with increasing x above x = 0.2. These features of γ strongly suggest that itinerant d electrons are tightly coupled with the evolution of magnetic orders in small and intermediate Mn concentrations.

The nature of competition between incommensurate (IC) and commensurate (C) antiferromagnetic (AF) orders in UPd 2 Si 2 was investigated by performing elastic neutron scattering experiments under uniaxial stress σ. It is found that applying σ along tetragonal [010] direction reduces the IC-AF order, and then stabilizes the C-AF order. The transition temperature from IC-to C-AF phases T Nl is enhanced from 109 K (σ = 0) to 112.5 K at (0.8 GPa), while the onset of IC-AF transition T Nh is unchanged from 132 K under σ. In addition, c-axis component q z of the IC-AF modulation at 115 K also increases from 0.736 (σ = 0) to 0.747 (0.8 GPa). The magnitude of C-AF moment at 5 K is estimated to be 2.2 µ B /U in the entire σ range presently investigated (σ ≤ 0.8 GPa). These features are similar to those obtained from the investigations using hydrostatic pressure p, indicating that applications of p and σ || [010] commonly induce the crystal strains which inherently affect a delicate balance of frustrated magnetic interactions between uranium 5f moments.

Bulk-sensitive microscopic measurements of buried magnetic domains are reported. Utilizing a new magneto-optical effect in the hard X-ray regime, referred to as X-ray magnetic circularly polarized emission, the internal transverse domains in a grainoriented electrical steel sheet are unambiguously observed. This allows the lateral shapes of the transverse domains to be successfully visualized. In addition, we discuss the magnetic domain structure of the supplementary domains below the surface from measurements performed at several pairs of incident and exit angles.