Superconductivity under high pressure in the binary compound CaLi2

被引：13

作者：

Debessai, M. ^{[1
]}

Matsuoka, T. ^{[1
,2
]}

Hamlin, J. J. ^{[1
]}

Gangopadhyay, A. K. ^{[1
]}

Schilling, J. S. ^{[1
]}

Shimizu, K. ^{[2
]}

Ohishi, Y. ^{[3
]}

机构：

[1] Washington Univ, Dept Phys, St Louis, MO 63130 USA

[2] Osaka Univ, KYOKUGEN, Ctr Quantum Sci & Technol Extreme Condit, Osaka 5608531, Japan

[3] Japan Synchrotron Radiat Res Inst SPring 8, Sayo, Hyougo 6795198, Japan

来源：

PHYSICAL REVIEW B | 2008年 / 78卷 / 21期

基金：

美国国家科学基金会;

关键词：

bifurcation; calcium alloys; crystal structure; elastic moduli; electrical resistivity; high-pressure effects; lithium alloys; magnetic susceptibility; solid-state phase transformations; X-ray diffraction;

D O I：

10.1103/PhysRevB.78.214517

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Feng predicted for CaLi2 highly anomalous properties with possible superconductivity under very high pressures, including for the hcp polymorph a significant lattice bifurcation at pressures above 47 GPa. More recently, however, Feng suggested that for pressures exceeding 20 GPa CaLi2 may dissociate into elemental Ca and Li. Here we present for hcp CaLi2 measurements of the electrical resistivity and ac susceptibility to low temperatures under pressures as high as 81 GPa. Pressure-induced superconductivity is observed in the pressure range of 11-81 GPa, with T-c reaching values as high as 13 K. X-ray diffraction studies to 54 GPa at 150 K reveal that hcp CaLi2 undergoes a structural phase transition above 23 GPa to orthorhombic but does not dissociate into elemental Ca and Li. In the hcp phase a fit of the equation of state with the Murnaghan equation yields the bulk modulus B-o=15(2) GPa and dB(o)/dP=3.2(6).

引用

页数：10

共 40 条

[1] Effects of static non-hydrostatic stress on the R lines of ruby single crystals [J].