Pressure dependent intermediate valence behavior in YbNiGa${}_4$ and YbNiIn${}_4$

Abstract

We report a comprehensive structural and valence study of the intermediate valent materials YbNiGa${}_4$ and YbNiIn${}_4$ under pressures up to 60 GPa. YbNiGa${}_4$ undergoes a smooth volume contraction and shows steady increase in Yb-valence with pressure, though the Yb-valence reaches saturation around 25 GPa. In YbNiIn${}_4$, a change in pressure dependence of the volume and a peak in Yb-valence suggest a pressure induced electronic topological transition occurs around 10-14 GPa. In the pressure region where YbNiIn${}_4$ and YbNiGa${}_4$ possess similar Yb-Yb spacings the Yb-valence reveals a precipitous drop. This drop is not captured by density-functional-theory calculations and implies that both the lattice degrees of freedom and the chemical environment play an important role in establishing the valence of Yb.

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• Pressure-Induced Valence Crossover and Novel Metamagnetic Behavior near the Antiferromagnetic Quantum Phase Transition of YbNi${}_3$Ga${}_9$
• Lifshitz transition from valence fluctuations in YbAl3
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Cited by in corpus (1)

• Valence instability across magnetostructural transition in USb${}_2$