Pressure-Induced Superconducting State of Europium Metal at Low Temperatures (Retracted Article)
Pressure-Induced Superconducting State of Europium Metal at Low Temperatures (Retracted Article)
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DOI：
10.1103/physrevlett.102.197002
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发表时间：
2009-05-15
影响因子：
8.6
通讯作者：
Shimizu, K.
中科院分区：
文献类型：
--
作者：
Debessai, M.;Matsuoka, T.;Shimizu, K.
二价Eu（4f（7），J=7/2）具有抑制超导电性的强局域磁矩。在足够的压力下，预计Eu将变成三价（4f（6），J=0）和弱的货车Vleck顺磁体，从而为可能的超导态打开了大门，类似于在0.79 K超导的Am金属（5 f（6），J=0）。我们目前的交流磁化率和电阻率测量Eu金属的温度为1.5-297 K的压力高达142 GPa。在大约80 GPa下，Eu在T-c接近或等于1.8 K时变成超导体; T-c随压力线性增加，在142 GPa下达到2.75 K。Eu金属因此成为周期表中第53个已知的元素超导体。
Divalent Eu (4f(7), J=7/2) possesses a strong local magnetic moment which suppresses superconductivity. Under sufficient pressure it is anticipated that Eu will become trivalent (4f(6), J=0) and a weak Van Vleck paramagnet, thus opening the door for a possible superconducting state, in analogy with Am metal (5f(6), J=0) which superconducts at 0.79 K. We present ac susceptibility and electrical resistivity measurements on Eu metal for temperatures 1.5-297 K to pressures as high as 142 GPa. At approximately 80 GPa Eu becomes superconducting at T-c similar or equal to 1.8 K; T-c increases linearly with pressure to 2.75 K at 142 GPa. Eu metal thus becomes the 53rd known elemental superconductor in the periodic table.