TY - JOUR
T1 - Unique electronic states of Eu-based compounds
AU - Onuki, Yoshichika
AU - Hedo, Masato
AU - Honda, Fuminori
N1 - Funding Information:
Acknowledgements We are very grateful for helpful discussions with K. Miyake, H. Shiba, T. Hotta, and R. Shiina. We thank H. Harima, T. Takeuchi, Y. Haga, Y. Uwatoko, J. Gouchi, T. Sakakibara, M. Nakashima, Y. Amako, S. Fujimori, I. Kawasaki, H. Ikeda, K. Kaneko, C. Tabata, D. Aoki, A. Nakamura, Y. Homma, N. Kawamura, K. Mimura, Y. Hiranaka, Y. Ashitomi, H. Akamine, W. Iha, M. Kakihana, and T. Nakama for collaborative studies. Special thanks also go to T. Takeuchi for critically reading this manuscript. This work was supported financially by JSPS KAKENHI Grant Nos. JP16H01078, JP18H04329, JP17K05547, JP15K05156, JP15KK0149, and JP19K21840.
Publisher Copyright:
© 2020 The Physical Society of Japan.
PY - 2020/9/14
Y1 - 2020/9/14
N2 - Pressure is a powerful tool for exploring novel phenomena in solid-state physics. We review the electronic states of single-crystalline EuT2X2 (T: transition metal, X: Si or Ge) and related compounds, together with the effect of pressure on these compounds. Eu ions in most of the Eu compounds are divalent (Eu2+), and the Eu2+ compounds order magnetically at low temperatures. The valence of the Eu ions in EuT2X2 and their related compounds can be, however, changed from divalent to nearly trivalent (Eu3+) by applying pressure. Several characteristic features were observed under pressure: the magnetic order is suppressed, as revealed by the Doniach phase diagram, the magnetic order changes to the first-order valence transition above a critical pressure, and the moderate heavy-fermion state appears around the magnetic quantum critical point. Typical electronic properties for the Eu3+ state were observed in EuPd3. In addition, a skyrmion lattice state was found for the Eu-based cubic chiral antiferromagnet EuPtSi.
AB - Pressure is a powerful tool for exploring novel phenomena in solid-state physics. We review the electronic states of single-crystalline EuT2X2 (T: transition metal, X: Si or Ge) and related compounds, together with the effect of pressure on these compounds. Eu ions in most of the Eu compounds are divalent (Eu2+), and the Eu2+ compounds order magnetically at low temperatures. The valence of the Eu ions in EuT2X2 and their related compounds can be, however, changed from divalent to nearly trivalent (Eu3+) by applying pressure. Several characteristic features were observed under pressure: the magnetic order is suppressed, as revealed by the Doniach phase diagram, the magnetic order changes to the first-order valence transition above a critical pressure, and the moderate heavy-fermion state appears around the magnetic quantum critical point. Typical electronic properties for the Eu3+ state were observed in EuPd3. In addition, a skyrmion lattice state was found for the Eu-based cubic chiral antiferromagnet EuPtSi.
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U2 - 10.7566/JPSJ.89.102001
DO - 10.7566/JPSJ.89.102001
M3 - Article
AN - SCOPUS:85092277945
VL - 89
JO - Journal of the Physical Society of Japan
JF - Journal of the Physical Society of Japan
SN - 0031-9015
IS - 10
M1 - 102001
ER -