CRYSTAL GROWTH METHOD FOR THIN FILM OF MULTIPLE OXIDE CONTAINING BISMUTH AS CONSTITUENT ELEMENT

PROBLEM TO BE SOLVED: To suppress the formation of a foreign phase and the deposition of impurities due to the deviation of Bi-containing composition from a target one and to obtain a high quality thin film of a multiple oxide contg. Bi by growing crystals by a vapor growth method while utilizing the growth self- terminating action of Bi. SOLUTION: Growth temp. and the amt. of oxidizing gas are set so as not to form Bi oxide but to form the objective multiple oxide, Bi is fed in excess more than other elements in the crystal growing environment to prevent a shortage of Bi and crystals are grown by a vapor growth method while utilizing the growth self-terminating action of Bi by which excess Bi is evaporated from a formed thin film. The multiple oxide is preferably Bi2 Sr2 CuO6 , Bi4 Ti3 O12 , Bi2 WO6 or Bi2 SrTa2 O9 . The vapor growth method is e.g. a molecular beam epitaxial method, a laser beam ablation method, a sputtering method or a chemical vapor growth method.