Intrinsic Properties of AFe2As2 (A = Ba, Sr) Single Crystal under Highly Hydrostatic Pressure Conditions
Intrinsic Properties of AFe2As2 (A = Ba, Sr) Single Crystal under Highly Hydrostatic Pressure Conditions
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DOI：
10.1143/jpsj.78.073706
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发表时间：
2009-07-01
影响因子：
1.7
通讯作者：
Uwatoko, Yoshiya
中科院分区：
文献类型：
--
作者：
Matsubayashi, Kazuyuki;Katayama, Naoyuki;Uwatoko, Yoshiya
利用立方顶锤装置测量了BaFe2As2和SrFe2As2单晶在加压条件下的电阻率和交流磁化率。对于BaFe2As2，反铁磁性(AF)和结构相变随着压力的增加而受到抑制。出乎意料的是，这些转变持续到8 Gpa，并且在所研究的压力范围内没有观察到超导转变的特征。另一方面，在接近5 Gpa的临界压力P-C附近，SrFe2As2的AF和结构相变崩塌，导致了大块超导的出现。超导体积分数在P-C以上突然增加，并在大约6 Gpa处显示一个中心的圆顶。我们的结果表明，大块超导相与AF/正交相竞争，并且只出现在四方相的狭窄压力区。
We measured the electrical resistivity and ac magnetic susceptibility of BaFe2As2 and SrFe2As2 single crystals under pressure using a cubic anvil apparatus. For BaFe2As2, the antiferromagnetic (AF) and structural transitions are suppressed with increasing pressure. Unexpectedly, these transitions persist up to 8 GPa, and no signature of a superconducting transition was observed in the pressure range investigated here. On the other hand, the AF and structural transitions of SrFe2As2 collapse at around the critical pressure P-C similar to 5 GPa, resulting in the appearance of bulk superconductivity. The superconducting volume fraction abruptly increases above P-C, and shows a dome centered at approximately 6 GPa. Our results suggest that the bulk superconducting phase competes with the AF/orthorhombic phase and only appears in the narrow pressure region of the tetragonal phase.