【摘要】：本文利用真空退火爐融煉束源金屬的單質(zhì)錠,作為束源爐的蒸發(fā)源；利用臭氧濃縮裝置獲得高濃度臭氧作為制備Bi系薄膜的氧化源；利用原子力顯微鏡研究了Bi, Sr,Ca和Cu金屬元素的蒸發(fā)速率。在此基礎(chǔ)上采用分子束外延法(MBE)制備Bi系氧化物薄膜。首先制備了結(jié)構(gòu)簡單,成相溫度寬的Bi2Sr2Cu06+δ薄膜,然后利用金屬源的蒸發(fā)速率并參考吸附系數(shù),制備了Bi2.1Cay Sr1.9-yCuO6+δ薄膜和Bi2Sr2CaCu2O8+δ(Bi-2212)薄膜,最后通過檢測手段分析研究了Bi系薄膜的結(jié)構(gòu)、表面形貌、結(jié)晶性和電學(xué)性能。本文的研究結(jié)果如下： (1)對實(shí)驗(yàn)設(shè)備進(jìn)行改造并優(yōu)化薄膜制備條件。結(jié)果是臭氧濃縮裝置中硅膠的溫度控制在-80±1℃：濃縮6h可獲得高于90mol%的臭氧并保持4小時以上；Bi, Sr, Ca和Cu金屬的蒸發(fā)速率與束源爐溫度呈線性關(guān)系,符合Clausius-Clapeyron方程的推導(dǎo)式：LogR=a/T+b。 (2)實(shí)驗(yàn)制備出了高質(zhì)量的Bi2Sr2Cu06+δ薄膜,Bi2,1CaySr1.9-yCuO6+δ薄膜隨著分子式中y值增大,c軸長度減小,導(dǎo)電性質(zhì)隨著y值不同而不同,當(dāng)y=0.8時,Tc,onset=90K。 (3)對于Bi2Sr2CaCu208+δ薄膜,在MgO(100)單晶襯底上外延生長Bi-2212薄膜時,當(dāng)襯底溫度為699℃,臭氧分壓為2.2×10-4Pa時,薄膜相純度最高且結(jié)晶質(zhì)量良好；相同制備條件下,SrTiO3(100)襯底上生長的Bi-2212薄膜結(jié)晶性得到改善,過渡層可以減緩MgO襯底與Bi-2212薄膜之間的錯配度,并提高了薄膜的超導(dǎo)轉(zhuǎn)變溫度。
[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 鹵1 鈩，

本文編號：2500372