Bi系氧化物薄膜分子束外延法制备及物理性能的研究
发布时间：2019-06-15 16:58
【摘要】：本文利用真空退火炉融炼束源金属的单质锭,作为束源炉的蒸发源；利用臭氧浓缩装置获得高浓度臭氧作为制备Bi系薄膜的氧化源；利用原子力显微镜研究了Bi, Sr,Ca和Cu金属元素的蒸发速率。在此基础上采用分子束外延法(MBE)制备Bi系氧化物薄膜。首先制备了结构简单,成相温度宽的Bi2Sr2Cu06+δ薄膜,然后利用金属源的蒸发速率并参考吸附系数,制备了Bi2.1Cay Sr1.9-yCuO6+δ薄膜和Bi2Sr2CaCu2O8+δ(Bi-2212)薄膜,最后通过检测手段分析研究了Bi系薄膜的结构、表面形貌、结晶性和电学性能。本文的研究结果如下： (1)对实验设备进行改造并优化薄膜制备条件。结果是臭氧浓缩装置中硅胶的温度控制在-80±1℃：浓缩6h可获得高于90mol%的臭氧并保持4小时以上；Bi, Sr, Ca和Cu金属的蒸发速率与束源炉温度呈线性关系,符合Clausius-Clapeyron方程的推导式：LogR=a/T+b。 (2)实验制备出了高质量的Bi2Sr2Cu06+δ薄膜,Bi2,1CaySr1.9-yCuO6+δ薄膜随着分子式中y值增大,c轴长度减小,导电性质随着y值不同而不同,当y=0.8时,Tc,onset=90K。 (3)对于Bi2Sr2CaCu208+δ薄膜,在MgO(100)单晶衬底上外延生长Bi-2212薄膜时,当衬底温度为699℃,臭氧分压为2.2×10-4Pa时,薄膜相纯度最高且结晶质量良好；相同制备条件下,SrTiO3(100)衬底上生长的Bi-2212薄膜结晶性得到改善,过渡层可以减缓MgO衬底与Bi-2212薄膜之间的错配度,并提高了薄膜的超导转变温度。
[Abstract]:In this paper, the single ingot of beam source metal was melted in vacuum annealing furnace as the evaporation source of beam source furnace, the high concentration ozone was obtained by ozone concentration device as the oxidation source for the preparation of Bi thin films, and the evaporation rate of Bi, Sr,Ca and Cu metal elements was studied by atomic force microscope (atomic force microscope). On this basis, Bi oxide thin films were prepared by molecular beam epitaxial (MBE). Bi2Sr2Cu06 未 thin films with simple structure and wide phase forming temperature were prepared, and then Bi2.1Cay Sr1.9-yCuO6 未 thin films and Bi2Sr2CaCu2O8 未 (Bi-2212) thin films were prepared by using the evaporation rate of metal source and reference adsorption coefficient. Finally, the structure, surface morphology, crystallization and electrical properties of Bi films were studied by means of detection. The results of this paper are as follows: (1) the experimental equipment is modified and the preparation conditions of thin films are optimized. The results show that the temperature of silica gel in ozone concentration unit is controlled at-80 卤1 鈩，
本文编号：2500372
[Abstract]:In this paper, the single ingot of beam source metal was melted in vacuum annealing furnace as the evaporation source of beam source furnace, the high concentration ozone was obtained by ozone concentration device as the oxidation source for the preparation of Bi thin films, and the evaporation rate of Bi, Sr,Ca and Cu metal elements was studied by atomic force microscope (atomic force microscope). On this basis, Bi oxide thin films were prepared by molecular beam epitaxial (MBE). Bi2Sr2Cu06 未 thin films with simple structure and wide phase forming temperature were prepared, and then Bi2.1Cay Sr1.9-yCuO6 未 thin films and Bi2Sr2CaCu2O8 未 (Bi-2212) thin films were prepared by using the evaporation rate of metal source and reference adsorption coefficient. Finally, the structure, surface morphology, crystallization and electrical properties of Bi films were studied by means of detection. The results of this paper are as follows: (1) the experimental equipment is modified and the preparation conditions of thin films are optimized. The results show that the temperature of silica gel in ozone concentration unit is controlled at-80 卤1 鈩，
本文编号：2500372
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