氩气退火时间对Fe(Se,Te)薄膜的性能影响研究

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

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CaF_(2)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。

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 CaF_(2) 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.