摘要
The recent discovery of superconductivity up to 32 K in the pressurized MoBreignites the interest in exploring high-Tc superconductors in transition-metal diborides. Inspired by that work, we turn our attention to the 5 d transition-metal diborides.Here we systematically investigate the responses of both structural and physical properties of WBand ReBto external pressure,which possess different types of boron layers. Similar to MoB, the pressure-induced superconductivity was also observed in WBabove 60 GPa with a maximum Tcof 15 K at 100 GPa, while no superconductivity was detected in ReBin this pressure range. Interestingly, the structures at ambient pressure for both WBand ReBpersist to high pressure without structural phase transitions. Theoretical calculations suggest that the ratio of flat boron layers in this class of transition-metal diborides may be crucial for the appearance of high Tc. The combined theoretical and experimental results highlight the effect of the geometry of boron layers on superconductivity and shed light on the exploration of novel high-Tcsuperconductors in borides.
基金
supported by the National Key R&D Program of China(Grant Nos.2018YFA0704300,2018YFE0202600,and 2017YFA0302903)
the National Natural Science Foundation of China(Grant Nos.U1932217,11974246,12004252,12174443,and 11774424)
the Natural Science Foundation of Shanghai(Grant No.19ZR1477300)
the Science and Technology Commission of Shanghai Municipality(Grant No.19JC1413900)
the Shanghai Science and Technology Plan(Grant No.21DZ2260400)
the Beijing Natural Science Foundation(Grant No.Z200005)
the Fundamental Research Funds for the Central Universities and Research Funds of Renmin University of China(RUC)(Grant Nos.18XNLG14,19XNLG13,19XNLG17,and 22XNKJ40)
support from Analytical Instrumentation Center(Grant No.SPSTAIC10112914),SPST,Shanghai Tech University。