Given the parallelism between the physical properties of Ce and Yb based magnets and heavy fermions due to the electron-hole symmetry, it has been rather odd that the transition temperature of the Yb based compounds is normally very small, as low as ∼ 1 K or even lower, whereas Ce counterparts may often have the transition temperature well exceeding 10 K. Here, we report our experimental discovery of the transition temperature reaching 20 K for the first time in a Yb based compound at ambient pressure. The Mn substitution at the Al site in an intermediate valence state of α-YbAlB4 not only induces antiferromagnetic transition at a record high temperature of 20 K but also transforms the heavy fermion liquid state in α-YbAlB4 into a highly resistive metallic state proximate to a Kondo insulator.
@article{arxiv.1803.09366,
title = {High temperature antiferromagnetism in Yb based heavy fermion systems proximate to a Kondo insulator},
author = {Shintaro Suzuki and Kou Takubo and Kentaro Kuga and Wataru Higemoto and Takashi U. Ito and Takahiro Tomita and Yasuyuki Shimura and Yosuke Matsumoto and Cedric Bareille and Hiroki Wadati and Shik Shin and Satoru Nakatsuji},
journal= {arXiv preprint arXiv:1803.09366},
year = {2021}
}