Growth of c-axis-oriented superconducting KFe2As2 thin films
Growth of c-axis-oriented superconducting KFe2As2 thin films
复制标题
c轴取向超导KFe2As2薄膜的生长
DOI：
10.1021/am5036016
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
H. Hiramatsu; S. Matsuda; H. Sato; T. Kamiya and H. Hosono
中科院分区：
文献类型：
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作者：
Y. Wang;H. Sato;Y. Toda;S. Ueda;H. Hiramatsu and H. Hosono;H. Hiramatsu; S. Matsuda; H. Sato; T. Kamiya and H. Hosono
KFe2As2 是一种铁基超导体，预计将表现出大的自旋霍尔电导率，而高质量薄膜的制造对于评估这种效应及其在自旋电子器件中的应用至关重要。由于两个固有特性，KFe2As2 的薄膜生长很困难；其极强的吸湿性和钾的高蒸气压。我们通过将使用富钾 KFe2As2 靶材的室温脉冲激光沉积与封装在真空石英玻璃管中后在 KFe2As2 粉末中热结晶相结合，以及在真空室和手套箱中的干燥 Ar 气氛中进行的所有过程解决了这些问题。在(La,Sr)(Al,Ta)O3单晶衬底上通过700℃晶化得到优化的KFe2As2薄膜，薄膜具有强c轴取向。电气测量是用油脂钝化保护的薄膜进行的，以阻止与大气的反应。 KFe2As2 薄膜在 3.7 K 时表现出超导转变。
KFe2As2, an iron-based superconductor, is expected to exhibit large spin Hall conductivity, and fabrication of high-quality thin films is requisite for evaluation of this effect and application to spintronics devices. Thin-film growth of KFe2As2is difficult because of two intrinsic properties; its extremely hygroscopic nature and the high vapor pressure of potassium. We solved these issues by combining room-temperature pulsed laser deposition using K-rich KFe2As2targets with thermal crystallization in KFe2As2powder after encapsulation in an evacuated silica-glass tube with all of the processes conducted in a vacuum chamber and a dry Ar atmosphere in a glovebox. The optimized KFe2As2films on (La,Sr)(Al,Ta)O3single-crystal substrates were obtained by crystallization at 700 °C, and they were stronglyc-axis oriented. The electrical measurements were performed with thin films protected by grease passivation to block reaction with the atmosphere. The KFe2As2films exhibited a superconductivity transition at 3.7 K.