Metallic conductivity in infinite-layer strontium iron oxide thin films reduced by calcium hydride
Metallic conductivity in infinite-layer strontium iron oxide thin films reduced by calcium hydride
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DOI：
10.1088/0022-3727/47/13/135304
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发表时间：
2014-03
期刊：
影响因子：
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通讯作者：
T. Katayama;A. Chikamatsu;Y. Hirose;H. Kumigashira;T. Fukumura;T. Hasegawa
中科院分区：
文献类型：
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作者：
T. Katayama;A. Chikamatsu;Y. Hirose;H. Kumigashira;T. Fukumura;T. Hasegawa
采用脉冲激光沉积法结合CaH2固相还原法在不同晶格参数的钙钛矿衬底上生长了SrFeO2单晶外延薄膜，并对其结构和输运性质进行了研究。在晶格匹配的KTaO 3（0 0 1）衬底上制备的高结晶薄膜具有金属导电性，而在SrTiO 3（0 0 1）和DyScO 3（1 1 0）衬底上制备的薄膜与块状SrFeO 2类似，为绝缘薄膜。根据对金属SrFeO2膜的霍尔测量，导电载流子被确定为n型（即，电子），载流子密度为3.1 × 1018 cm−3，300 K时迁移率为10.2 cm 2 V−1 s−1。这表明SrFeO_2薄膜中的电子载流子是由氧空位或氢离子提供的。
Single-crystalline epitaxial SrFeO2 thin films were grown on perovskite substrates with various lattice parameters by combining pulsed laser deposition method with solid-phase reduction using CaH2, and these structural and transport properties were investigated. The highly crystalline films prepared on lattice-matched KTaO3(0 0 1) substrate exhibited metallic conduction, while those prepared on SrTiO3(0 0 1) and DyScO3(1 1 0) substrates were insulating films, in analogy to bulk SrFeO2. From Hall measurements on the metallic SrFeO2 films, the conduction carriers were determined to be n-type (i.e., electrons) with a carrier density of 3.1 × 1018 cm−3 and a mobility of 10.2 cm2 V−1 s−1 at 300 K. It is suggested that the electron carriers are supplied by oxygen vacancies or hydrogen ions in the metallic SrFeO2 films.