High field x-ray diffraction study on a magnetic-field-induced valence transition in YbInCu4

TL;DR

This study uses high-field x-ray diffraction to observe a first-order valence transition in YbInCu4 induced by magnetic fields exceeding 27 T, revealing structural changes and phase coexistence.

Contribution

First high-field x-ray diffraction experiment demonstrating structural evidence of a magnetic-field-induced valence transition in YbInCu4.

Findings

Significant change in Bragg reflection profile at 27 T indicating a structural transition.

Observation of phase coexistence near the transition field.

Bragg peak intensity correlates with magnetization.

Abstract

We report the first high-field x-ray diffraction experiment using synchrotron x-rays and pulsed magnetic fields exceeding 30 T. Lattice deformation due to a magnetic-field-induced valence transition in YbInCu4 is studied. It has been found that the Bragg reflection profile at 32 K changes significantly at around 27 T due to the structural transition. In the vicinity of the transition field the low-field and the high-field phases are observed simultaneously as the two distinct Bragg reflection peaks: This is a direct evidence of the fact that the field-induced valence state transition is the first order phase transition. The field-dependence of the low-field-phase Bragg peak intensity is found to be scaled with the magnetization.