In the 1970s, X-rays were thought to be practically useless for studies of magnetism in comparison with neutrons due to their smaller interaction cross-section with magnetic moments. However, in the 1980s some pioneering advances in X-ray studies of magnetism were successfully demonstrated by applying intense X-rays at synchrotron facilities. X-ray magnetic circular dichroism (XMCD) in the hard and soft regimes was first reported by G. Schütz in 1987 [1] and C. T. Chen in 1990 [2], respectively, and these seminal studies became the beginning of the application of XMCD spectroscopy to a wide range of magnetic materials. Today, magnetic analysis using XMCD spectroscopy has become a very powerful tool for characterizing the magnetic properties of materials. 

In this talk, after a short introduction of SPring-8 and the other synchrotron facilities in Japan, I will present recent XMCD studies and related technical developments which have been conducted at BL25SU, a soft X-ray beamline for public use at SPring-8 [3]. For the technical developments, I will introduce the scanning-type XMCD microscopy with a superconducting magnet [4], and the XMCD measurement technique using a pulse magnet generating 40 T [5]. For their applications, I will mainly show some results in magnetic domain observations in permanent magnets. A major upgrade of the beamline was conducted in 2014 and I will illustrate this and report on its current status.

[1] G. Schütz et al., Phys. Rev. Lett. 58, 737 (1987).

[2] C. T. Chen et al., Phys. Rev. B 42, 7262 (1990).

[3] T. Nakamura and M. Suzuki, J. Phys. Soc. Jpn. 82, 021006 (2013).

[4] Y. Kotani et al., J. Synchrotron Rad. 25 (2018).

[5] T. Nakamura et al., Appl. Phys. Express 4, 066602 (2011).