Pressure-Induced Valence Crossover and Novel Metamagnetic Behavior near the Antiferromagnetic Quantum Phase Transition of YbNi$_{3}$Ga$_{9}$

TL;DR

This study investigates how pressure influences valence states and magnetic behavior in YbNi$_{3}$Ga$_{9}$, revealing a valence crossover and a first-order metamagnetic transition near an antiferromagnetic quantum phase transition.

Contribution

It uncovers a pressure-induced valence crossover and a novel metamagnetic transition linked to critical valence fluctuations in YbNi$_{3}$Ga$_{9}$.

Findings

Pressure induces a Yb valence crossover.

A first-order metamagnetic transition occurs below 9 GPa.

Critical valence fluctuations are associated with the metamagnetic behavior.

Abstract

We report electrical resistivity, ac magnetic susceptibility and X-ray absorption spectroscopy measurements of intermediate valence YbNi$_{3}$Ga$_{9}$ under pressure and magnetic field. We have revealed a characteristic pressure-induced Yb valence crossover within the temperature-pressure phase diagram, and a first-order metamagnetic transition is found below $P_{\rm c}$ $\sim$ 9 GPa where the system undergoes a pressure-induced antiferromagnetic transition. As a possible origin of the metamagnetic behavior, a critical valence fluctuation emerging near the critical point of the first-order valence transition is discussed on the basis of the temperature-field-pressure phase diagram.