Abstract
Prior to the superconducting transition at Tc≈2.3K, Mo3Sb7 undergoes a symmetry-lowering, cubic-to-tetragonal structural transition at Ts=53K. We have monitored the pressure dependence of these two transitions by measuring the resistivity of Mo3Sb7 single crystals under various hydrostatic pressures up to 15 GPa. The application of external pressure enhances Tc but suppresses Ts until Pc≈10GPa, above which a pressure-induced first-order structural transition takes place and is manifested by the phase coexistence in the pressure range 8≤P≤12GPa. The cubic phase above 12 GPa is also found to be superconducting with a higher Tc≈6K that decreases slightly with further increasing pressure. The variations with pressure of Tc and Ts satisfy the Bilbro-McMillan equation, i.e. TcnTs1-n= constant, thus suggesting the competition of superconductivity with the structural transition that has been proposed to be accompanied with a spin-gap formation at Ts. Our first-principles calculations suggest the importance of magnetism that competes with the superconductivity in Mo3Sb7.
| Original language | English |
|---|---|
| Article number | 224508 |
| Journal | Physical Review B |
| Volume | 94 |
| Issue number | 22 |
| DOIs | |
| State | Published - Dec 14 2016 |
Funding
This paper was supported by the National Basic Research Program of China (Grant No. 2014CB921500), the National Science Foundation of China (Grant No. 11574377), the Strategic Priority Research Program and the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences (Grants No. XDB07020100 and No. QYZDB-SSW-SLH013), and the Opening Project of Wuhan National High Magnetic Field Center (Grant No. 2015KF22), Huazhong University of Science and Technology. Work at Oak Ridge National Laboratory was supported by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Science and Engineering Division.