High pressure structural and magnetic studies of LaFe 12 B 6

Abstract

Abstract The study of the structural and magnetic properties of LaFe 12 B 6 under high pressure has been performed by combining angle-dispersive x-ray powder diffraction at room temperature up to 14 GPa and magnetization measurements up to 1 GPa. At ambient pressure, the itinerant-electron compound LaFe 12 B 6 exhibits an antiferromagnetic ground state below T N =36 K. It is demonstrated that the antiferromagnetic state can be transformed into a ferromagnetic state via a field-induced first-order metamagnetic transition accompanied with a large magnetic hysteresis. The x-ray diffraction measurements under pressure reveal that the ambient pressure crystal structure of LaFe 12 B 6 is preserved up to 14 GPa with a decrease of the unit cell parameters. A compressibility value of κ=4.90 10 −3 GPa −1 has been determined. The application of an external pressure leads also to the progressive decrease of the Neel temperature d T N /d P =−4.5 K GPa −1 . In addition a large pressure effect on the critical field μ 0 H cr of the metamagnetic transition, dμ 0 H cr / dP =24 T GPa −1 , was discovered. This clearly indicates the crucial role of volume effect on the itinerant-electron metamagnetic transition.