| 摘要 |
PURPOSE:To obtain a lithium niobate single crystal thin film having large thickness and excellent optical properties by contacting a lithium tantalate substrate with a molten material having a specific composition and carrying out the epitaxial growth of a lithium niobate single crystal thin film in a state to have a lattice constant matched with that of the substrate. CONSTITUTION:A molten material composed of Li2O, V2O5, Na2O and MgO and having the following composition is prepared beforehand. The contents of Li2O, V2O5 and Nb2O5 fall within a compositional area defined by three points A(49.49, 45.46, 5.05), B(42.81, 22.94, 34.25) and C(11.11, 80, 8.89) show in the figure and the molar ratios of Na2/Li2O and MgO/Nb2O5 are 2/98 to 93.5/6.5 and 0.2/99.8 to 40/60, respectively. A lithium tantalate substrate is made to contact with the molten material to match the lattice constant of the a-axis of the substrate to that of the a-axis of the lithium niobate single crystal thin film to be grown on the substrate. The lithium niobate single crystal thin film is grown on the substrate by epitaxial growth process. |
