Field-induced valence fluctuations in YbB12
Field-induced valence fluctuations in YbB12
复制标题
YbB12 中场引起的价态波动
DOI：
10.1103/physrevb.103.115103
复制
发表时间：
2021
影响因子：
3.7
通讯作者：
Iga F.
中科院分区：
文献类型：
--
作者：
Kurihara R.;Miyake A.;Tokunaga M.;Ikeda A.;Matsuda Y. H.;Miyata A.;Gorbunov D. I.;Nomura T.;Zherlitsyn S.;Wosnitza J.;Iga F.
我们进行了高达59 T的强磁场超声实验来研究Yb离子的价态涨落。在零磁场下，纵向弹性常数、横向弹性常数和C11−C12/2以及体模量在35 K附近随曲率的变化而变硬，表明原子价涨落对弹性常数的贡献很小.当在低温下施加高磁场时，表现出高于场致绝缘体-金属转变信号场致价态波动的软化。此外，在升高的温度下，场致软化发生在甚至更低的领域和不断减少的领域。基于双带模型的多极极化率分析表明，除了绝缘体能隙的减小外，多极应变相互作用的增强也是导致绝缘体软化的原因。这一分析表明，场致Yb的价态涨落导致的体积模量的不稳定性。
We performed high-magnetic-field ultrasonic experiments onup to 59 T to investigate the valence fluctuations in Yb ions. In zero field, the longitudinal elastic constant, the transverse elastic constantsand C11−C12/2, and the bulk modulusshow a hardening with a change of curvature at around 35 K indicating a small contribution of valence fluctuations to the elastic constants. When high magnetic fields are applied at low temperatures,exhibits a softening above a field-induced insulator-metal transition signaling field-induced valence fluctuations. Furthermore, at elevated temperatures, the field-induced softening oftakes place at even lower fields anddecreases continuously with field. Our analysis using the multipole susceptibility based on a two-band model reveals that the softening oforiginates from the enhancement of multipole-strain interaction in addition to the decrease of the insulator energy gap. This analysis indicates that field-induced valence fluctuations of Yb cause the instability of the bulk modulus.