X-ray magnetic Compton-profile measurements on SmCo5 by using pulsed high magnetic field

A pulse magnet is applied to an experiment on magnetic Compton scattering using circularly polarized synchrotron-radiation X-rays. The sample is c-asis oriented SmCo5, which is known to be a hard magnetic materials. Consecutive pulsed magnetic fields of 11.7 tesla are used to repeatedly reverse the magnetization direction of the sample. The measurement is done with residual magnetization of the sample at room temperature. The magnetic Compton profile is found to be well-reproduced by a combination of a theoretical Sm-4f profile and an experimental Co profile. On the assumption that the Co spin moment in the hexagonal symmetry is 1.56 mu(B), the Sm-4f spin moment is evaluated to be -1.79 mu(B), which is quite small compared with the expected spin moment 3.57 mu(B) for the Sm ground state (J = 5/2 M(J) = 5/2). This experiment suggests for the first time the feasibility of using pulse magnets for X-ray magnetic scattering and absorption measurements on hard magnetic materials.