High Field X-ray Diffraction Study on a Magnetic-Field-Induced Valence Transition in YbInCu₄

Abstract

We report the first high-field x-ray diffraction experiment using synchrotron\nx-rays and pulsed magnetic fields exceeding 30 T. Lattice deformation due to a\nmagnetic-field-induced valence transition in YbInCu4 is studied. It has been\nfound that the Bragg reflection profile at 32 K changes significantly at around\n27 T due to the structural transition. In the vicinity of the transition field\nthe low-field and the high-field phases are observed simultaneously as the two\ndistinct Bragg reflection peaks: This is a direct evidence of the fact that the\nfield-induced valence state transition is the first order phase transition. The\nfield-dependence of the low-field-phase Bragg peak intensity is found to be\nscaled with the magnetization.\n