||Observation of Systematic Variation in Yb Ion Valence as a Function of Interatomic Spacing in Icosahedral Approximant Crystals
Hayashi, Minami ,
Deguchi, Kazuhiko ,
Matsukawa, Shuya ,
Imura, KeiichiroSato, Noriaki K.
Journal of the Physical Society of Japan
043702 , 2017-03-13 , 日本物理学会
We discovered two alloy systems, Pd–Ga–Yb and Pd–Ge–Yb, that belong to the Tsai-type 1/1 approximant to the Au–Al–Yb quasicrystal exhibiting the unusual quantum criticality and show a similar behavior to Kondo lattice systems with a magnetically ordered ground state. Combining the results of other Yb-based approximant crystals, we find that there is a systematic variation in the Yb ion valence vs the lattice constant. This proves that the Au–Al–Yb approximant is located at the border of the valence change, in favor of the idea that the valence fluctuation plays a crucial role in the quantum criticality of the Au–Al–Yb system.