Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan.
Toyota Physical and Chemical Research Institute, 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan.
Phys Rev Lett. 2015 Dec 11;115(24):246402. doi: 10.1103/PhysRevLett.115.246402. Epub 2015 Dec 8.
We performed high-pressure study for a Mott insulator BaFe_{2}S_{3}, by measuring dc resistivity and ac susceptibility up to 15 GPa. We found that the antiferromagnetic insulating state at the ambient pressure is transformed into a metallic state at the critical pressure, P_{c}=10 GPa, and the superconductivity with the optimum T_{c}=24 K emerges above P_{c}. Furthermore, we found that the metal-insulator transition (Mott transition) boundary terminates at a critical point around 10 GPa and 75 K. The obtained pressure-temperature (P-T) phase diagram is similar to those of the organic and fullerene compounds; namely, BaFe_{2}S_{3} is the first inorganic superconductor in the vicinity of bandwidth control type Mott transition.
我们对莫特绝缘体 BaFe_{2}S_{3} 进行了高压研究,通过测量直流电阻率和交流磁化率,最高可达 15 GPa。我们发现,常压下的反铁磁绝缘态在临界压力 P_{c}=10 GPa 下转变为金属态,超导转变温度 T_{c}=24 K 出现在 P_{c}以上。此外,我们发现金属-绝缘体转变(莫特转变)边界在约 10 GPa 和 75 K 处终止于临界点。得到的压力-温度(P-T)相图与有机和富勒烯化合物的相图相似;即 BaFe_{2}S_{3} 是临近带宽控制型莫特转变的第一个无机超导体。