氩气退火时间对Fe(Se,Te)薄膜的性能影响研究

人工晶体学报 ›› 2022, Vol. 51 ›› Issue (4): 660-665.

氩气退火时间对Fe(Se,Te)薄膜的性能影响研究

罗露林^1,2, 张洁^1,2, 羊新胜¹, 赵勇¹

1.西南交通大学超导与新能源研究开发中心,成都 610031;
2.西南交通大学物理科学与技术学院,成都 610031

收稿日期:2022-01-24 出版日期:2022-04-15 发布日期:2022-05-16
通讯作者: 羊新胜,博士,副教授。E-mail:xsyang@swjtu.edu.cn
作者简介:罗露林(1996—),男,四川省人,硕士研究生。E-mail:2668075778@qq.com
基金资助:
国家自然科学基金(51271155,51377138,51877180);国家重点研发计划(2017YFE0301402);国家高技术研究发展计划 (2014AA032701);四川应用基础研究项目(2018JY0003)

Effect of Argon Annealing Time on Properties of Fe(Se,Te) Thin Films

LUO Lulin^1,2, ZHANG Jie^1,2, YANG Xinsheng¹, ZHAO Yong¹

1. Superconductivity and New Energy R & D Center, Southwest Jiaotong University, Chengdu 610031, China;
2. School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610031, China

Received:2022-01-24 Online:2022-04-15 Published:2022-05-16

摘要/Abstract

摘要： 作为一种铁基超导薄膜,Fe(Se,Te)薄膜具有晶体结构简单、所包含的元素较少、易于合成的特点,不仅有利于超导机理研究而且有着潜在的技术应用价值。本文通过磁控溅射在温度为320 ℃的CaF₂单晶衬底上制备了Fe(Se,Te)薄膜,并在氩气氛围下进行了退火处理。研究了退火时间对Fe(Se,Te)薄膜的晶体结构、微观形貌、成分组成以及电输运特性的影响。结果表明:Fe(Se,Te)薄膜的结晶性较好,退火有助于消除薄膜样品中的FeSe相,薄膜的晶格常数c对退火不敏感,退火后薄膜晶粒尺寸变大;Fe(Se,Te)薄膜成分与靶材的名义组分存在一定的偏差,退火时间越长,Fe(Se,Te)薄膜表面的颗粒越密集;Fe(Se,Te)薄膜的电阻随温度升高而减小,呈现出半导体特性,退火3 h后电阻明显增大。

关键词: Fe(Se,Te)薄膜, 磁控溅射, 氩气退火, 电输运特性, 铁基超导薄膜

Abstract: As one of the iron-based superconducting thin films, Fe(Se,Te) thin films have the simplest crystal structure, fewer elements and easy to be synthesized, which is conducive to the study of superconductivity mechanism and has potential technical applications. In this paper, Fe(Se,Te) thin films were prepared by magnetron sputtering on CaF₂ single crystal substrates at 320 ℃ and annealed in argon atmosphere. The effects of annealing time on the crystal structure, surface morphology, composition and electrical transport characteristics of Fe(Se,Te) thin films were investigated. The results show that the crystallinity of Fe(Se,Te) thin films is good, annealing is helpful to eliminate FeSe phase in the thin films, lattice constant c is not sensitive to annealing, and the grain size of the thin films increases after annealing. The composition of Fe(Se,Te) thin films is different from the nominal composition of target material, and the longer the annealing time, the denser the particles on the Fe(Se,Te) films surface. The resistance of Fe(Se,Te) thin films decreases with the increase of temperature, showing semiconductor characteristics, and the resistance increases obviously after 3 h annealing.

Key words: Fe(Se,Te) thin film, magnetron sputtering, argon annealing, electrical transport characteristic, iron-based superconducting thin film

中图分类号:

罗露林, 张洁, 羊新胜, 赵勇. 氩气退火时间对Fe(Se,Te)薄膜的性能影响研究[J]. 人工晶体学报, 2022, 51(4): 660-665.

LUO Lulin, ZHANG Jie, YANG Xinsheng, ZHAO Yong. Effect of Argon Annealing Time on Properties of Fe(Se,Te) Thin Films[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2022, 51(4): 660-665.

参考文献

[1] KAMIHARA Y, WATANABE T, HIRANO M, et al. Iron-based layered superconductor La[O_1-xF_x]FeAs (x=0.05-0.12) with T_c=26 K[J]. Journal of the American Chemical Society, 2008, 130(11): 3296-3297.
[2] WEI Z, LI H O, HONG W L, et al. Superconductivity at 57.3 K in La-doped iron-based layered compound Sm_0.95La_0.05O_0.85F_0.15FeAs[J]. Journal of Superconductivity and Novel Magnetism, 2008, 21(4): 213-215.
[3] PITCHER M J, PARKER D R, ADAMSON P, et al. Structure and superconductivity of LiFeAs[J]. Chemical Communications, 2008(45): 5918.
[4] ROTTER M, TEGEL M, JOHRENDT D. Superconductivity at 38 K in the iron arsenide (Ba_1-xK_x)Fe₂As₂[J]. Physical Review Letters, 2008, 101(10): 107006.
[5] HSU F C, LUO J Y, YEH K W, et al. Superconductivity in the PbO-type structure α-FeSe[J]. PNAS, 2008, 105(38): 14262-14264.
[6] MEDVEDEV S, MCQUEEN T M, TROYAN I A, et al. Electronic and magnetic phase diagram of β-Fe_1.01Se with superconductivity at 36.7 K under pressure[J]. Nature Materials, 2009, 8(8): 630-633.
[7] KATAYAMA N, JI S, LOUCA D, et al. Investigation of the spin-glass regime between the antiferromagnetic and superconducting phases in Fe_1+ySe_xTe_1-x[J]. Journal of the Physical Society of Japan, 2010, 79(11): 113702.
[8] AHMAD D, CHOI W J, SEO Y I, et al. Thermally activated flux flow in superconducting epitaxial FeSe_0.6Te_0.4 thin film[J]. Results in Physics, 2017, 7: 16-20.
[9] GEETHA KUMARY T, BAISNAB D K, JANAKI J, et al. Superconducting Fe_1+δSe_1-x Te_x thin films: growth, characterization and properties[J]. Superconductor Science and Technology, 2009, 22(9): 095018.
[10] BELLINGERI E, BUZIO R, GERBI A, et al. High quality epitaxial FeSe_0.5Te_0.5 thin films grown on SrTiO₃ substrates by pulsed laser deposition[J]. Superconductor Science and Technology, 2009, 22(10): 105007.
[11] SI W D, LIN Z W, JIE Q, et al. Enhanced superconducting transition temperature in FeSe_0.5Te_0.5 thin films[J]. Applied Physics Letters, 2009, 95(5): 052504.
[12] MOUSAVI T, GROVENOR C, SPELLER S. Characterization of superconducting Fe_y(Se_1-xTe_x) thin films deposited on MgO substrates by sputtering[J]. Journal of Materials Science, 2015, 50(21): 6970-6978.
[13] MOUSAVI T, GROVENOR C, SPELLER S. Effects of processing condition on the properties of Fe(Se, Te) thin films grown by sputtering[J]. IEEE Transactions on Applied Superconductivity, 2014, 25(3): 1-4.
[14] SPELLER S C, AKSOY C, SAYDAM M, et al. Analysis of Fe_ySe_1-xTe_x thin films grown by radio frequency sputtering[J]. Superconductor Science and Technology, 2011, 24(7): 075023.
[15] MELE P, MATSUMOTO K, FUJITA K, et al. Fe-Te-Se epitaxial thin films with enhanced superconducting properties[J]. Superconductor Science and Technology, 2012, 25(8): 084021.
[16] RÖßLER S, CHERIAN D, HARIKRISHNAN S, et al. Disorder-driven electronic localization and phase separation in superconducting Fe_1+yTe_0.5Se_0.5 single crystals[EB/OL]. 2012: arXiv: 1209.1211[cond-mat.supr-con]. https://arxiv.org/abs/1209.1211.