And a method for producing the material has a Bi ▲ under 2 ▼ WO ▲ under 6 ▼ based crystal film in which C-axis orientation

摘要

PURPOSE:To form a C-axis oriented Bi2WO6 crystal film in a low temp. range by repeating the operations of first evaporating Bi onto the surface of a base material on which a vapor deposited layer of SO3 is formed, then evaporating WO3 thereof to form the vapor deposited layer. CONSTITUTION:The vapor deposited WO3 layer is formed on the surface of the substrate consisting of an MgO single crystal, etc., in a vacuum vessel where a slight quantity of oxygen exists to form the base material having the (001) face of the WO3 single crystal on the surface. The substrate is heated to evaporate the Bi first so that the vapor deposited Bi2O2 layer corresponding to the thickness of the Bi2O2 in the C-axis direction of the unit lattice of the Bi2O6 crystal is formed thereon. The WO3 is then evaporated to form the vapor deposited layer corresponding to the thickness of the WO4 in the C-axis direction of the unit lattice of the Bi2WO6 crystal. The evaporation of the Bi and WO3 is repeated. The evaporation of the WO3 is otherwise substd. partly with the evaporation of MoO3. The material having the C-axis oriented Bi2WO6 crystal film which is preferably as a dielectric or piezo-electric material is thereby obtd.