Magnetization Process of the Kondo Insulator YbB12 in Ultrahigh Magnetic Fields
Abstract
The magnetization process of the Kondo insulator YbB12 has been unveiled in ultrahigh magnetic fields of up to 120 T at 4.2 K. We have found a novel metamagnetic transition at Bc2 = 102 T in addition to the previously known transition at Bc1 = 55 T. It has also been observed that the magnetization tends to saturate at around 112 T. Within the rigid band model, the two-energy-gap structure in the density of states (DOS) explains the successive two-step metamagnetism as a result of the Zeeman effect of the DOS. The metamagnetic transition at Bc1 occurs along with an insulator-metal transition and the field-induced phase is expected to be a heavy fermion metallic state. The Kondo effect can weaken at the second transition of Bc2, as theoretically found in the successive two-metamagnetic-transition process in the Kondo semimetal CeNiSn.
- Publication:
-
Journal of the Physical Society of Japan
- Pub Date:
- May 2017
- DOI:
- 10.7566/JPSJ.86.054710
- Bibcode:
- 2017JPSJ...86e4710T