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arXiv · 2305.16853

Variation of Pressure-Induced Valence Transition with Approximation Degree in Yb-Based Quasicrystalline Approximants

Keiichiro Imura·Yuki Yoneyama·Hideyuki Ando·Noriyuki Kabeya·Hitoshi Yamaoka·Nozomu Hiraoka·Hirofumi Ishii·Tsutomu Ishimasa·Noriaki K. Sato
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Abstract

We have synthesized new Tsai-type Yb-based intermediate-valence approximant crystals (ACs) with different degree of approximation to quasicrystal, Zn--Au--Yb 1/1 and 2/1 AC, and studied the external pressure effect on their Yb mean-valence $ν$. Whereas 1/1 AC distinctly exhibits a first-order-like jump in $ν$ at a transition pressure $P_{\rm v}$, 2/1 AC only shows an indistinct anomaly at $P_{\rm v}$. We have also studied the pressure dependence of the $ν$ of Au--Al--Yb 1/1 AC, which is a prototypal AC exhibiting pressure-induced quantum criticality. It shows a continuous valence anomaly at a critical pressure $P_{\rm c}$ where the magnetic susceptibility diverges toward zero temperature, in contrast to the valence jump in the Zn--Au--Yb 1/1 AC. These results are discussed based on a theoretical model of quantum critical valence fluctuation.

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Keiichiro Imura, Yuki Yoneyama, Hideyuki Ando, Noriyuki Kabeya, Hitoshi Yamaoka, Nozomu Hiraoka, Hirofumi Ishii, Tsutomu Ishimasa, Noriaki K. Sato. 2023-05-26. Variation of Pressure-Induced Valence Transition with Approximation Degree in Yb-Based Quasicrystalline Approximants. https://doi.org/10.7566/jpsj.92.093701

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