Mg-Cu-Y金属玻璃薄膜的短程序结构及其在Tx温度之上的纳米晶化行为.docVIP

  Short Range Order in Mg-Cu-Y Metallic Glass Thin Film and its Nano-crystallization Behavior above Tx# 5 10 15 20 25 30 WU Ge1, MIAO Xiangshui1, TANG Qinghua2, YU Niannian1** (1. Dept. of Electronic Sci.Tech., Huazhong University of Sci.Tech., Wuhan 430074, National Laboratory for Optoelectronics, Wuhan 430074; 2. Dept. of Electronic Sci.Tech., Huazhong University of Sci.Tech., Wuhan 430074) Abstract: Mg-Cu-Y metallic glass thin films with a large supercooled liquid region (?TX=57 K) and a smooth surface (Ra=0.485 nm) were deposited by DC magnetron sputtering. By changing the sputtering parameters such as sputtering power and Ar pressure, the amorphous Mg-Cu-Y films with different compositions and different thicknesses were fabricated easily. The surface morphology, microstructure, thermal and crystallization properties of the Mg58Cu29Y13 films were investigated. Inverse Fourier transmission images of the HRTEM result revealed that there exists icosahedra-like short range order structure in the as-deposited Mg58Cu29Y13 metallic glass thin film, which agrees well with our molecular dynamics simulation. However, the crystallization behavior of thin films was much different from that of bulk metallic glass. Mg58Cu29Y13 metallic glass thin films showed phase separation before the nucleation. Because of the high nucleation rate and low nucleus growth rate in the nucleation process, the films exhibited many nano-crystals with 10 nm diameter when they were annealed above crystallization temperature. Key words: Metallic glass thin films; magnetron sputtering; short range ordering; nanocrystallization 0 Introduction Metallic glass materials with relatively high thermal stability and low critical cooling rates have attracted great attention to the fundamental application research due to their potential use in engineering and electronic applications. These bulk metallic glasses (BMGs) are known to possess distinctive properties, including extraordinarily high strength, h