Kohei Nishiyama, Takeshi Mito, Ko ichi Ueda, Takehide Koyama, Takao Kohara, Gabriel Pristáš, Slavomír Gabáni, Marián Reiffers, Karol Flachbart, Yasuhiro Komaki, Mitsutane Kokubu, Hideto Fukazawa, Yoh Kohori, Nao Takeshita, Natalia Shitsevalova
Journal of the Korean Physical Society, 62(12) 2024-2027, Jul, 2013 Peer-reviewed
We report the first high-pressure 11B-NMR studies above 3 GPa on the intermediate-valence semiconductor SmB6. A 11B-NMR line obtained at 4.9 GPa, the highest pressure for the measurements, and at 1.9 K shows quite similar a line shape to that at ambient pressure, indicating no structural or magnetic phase transition up to this pressure. The temperature dependence of the spin lattice relaxation rate 1/T 1 at 4.9 GPa still exhibits an activation-type temperature dependence characteristic of semiconductors, which reveals an obvious decrease in the insulating gap by about 30% compared to the gap at ambient pressure. The present experimental facts of a finite insulator gap and no magnetic order at 4.9 GPa are consistent with recent transport measurements performed under better hydrostatic pressures. © 2013 The Korean Physical Society.