%0 Journal Article %1 PhysRevB.103.115103 %A Kurihara, R %A Miyake, A %A Tokunaga, M %A Ikeda, A %A Matsuda, Y H %A Miyata, A %A Gorbunov, D I %A Nomura, T %A Zherlitsyn, S %A Wosnitza, J %A Iga, F %D 2021 %I American Physical Society %J Phys. Rev. B %K a %N 11 %P 115103 %R 10.1103/PhysRevB.103.115103 %T Field-induced valence fluctuations in YbB$_12$ %U https://journals.aps.org/prb/pdf/10.1103/PhysRevB.103.115103 %V 103 %X We performed high-magnetic-field ultrasonic experiments on YbB12 up to 59 T to investigate the valence fluctuations in Yb ions. In zero field, the longitudinal elastic constant C11, the transverse elastic constants C44 and (C11−C12)/2, and the bulk modulus CB show 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, CB exhibits a softening above a field-induced insulator-metal transition signaling field-induced valence fluctuations. Furthermore, at elevated temperatures, the field-induced softening of CB takes place at even lower fields and CB decreases continuously with field. Our analysis using the multipole susceptibility based on a two-band model reveals that the softening of CB originates 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 CB.

@article{PhysRevB.103.115103, abstract = {We performed high-magnetic-field ultrasonic experiments on YbB12 up to 59 T to investigate the valence fluctuations in Yb ions. In zero field, the longitudinal elastic constant C11, the transverse elastic constants C44 and (C11−C12)/2, and the bulk modulus CB show 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, CB exhibits a softening above a field-induced insulator-metal transition signaling field-induced valence fluctuations. Furthermore, at elevated temperatures, the field-induced softening of CB takes place at even lower fields and CB decreases continuously with field. Our analysis using the multipole susceptibility based on a two-band model reveals that the softening of CB originates 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 CB.}, added-at = {2021-10-14T16:55:20.000+0200}, author = {Kurihara, R and Miyake, A and Tokunaga, M and Ikeda, A and Matsuda, Y H and Miyata, A and Gorbunov, D I and Nomura, T and Zherlitsyn, S and Wosnitza, J and Iga, F}, biburl = {https://www.bibsonomy.org/bibtex/203e7fdd9354091630ba0b14582a2709b/ctqmat}, day = 3, description = {Field-induced valence fluctuations in YbB12}, doi = {10.1103/PhysRevB.103.115103}, interhash = {2784536044cca8f6d1efdff5a74d728a}, intrahash = {03e7fdd9354091630ba0b14582a2709b}, journal = {Phys. Rev. B}, keywords = {a}, month = {03}, number = 11, numpages = {14}, pages = 115103, publisher = {American Physical Society}, timestamp = {2023-10-19T10:28:39.000+0200}, title = {Field-induced valence fluctuations in YbB$_{\mathbf{12}}$}, url = {https://journals.aps.org/prb/pdf/10.1103/PhysRevB.103.115103}, volume = 103, year = 2021 }