Abstract: A method of adjusting the in-plane lattice constant of a substrate and an in-plane lattice constant adjusted substrate are provided. A crystalline substrate (1) made of SrTiO3 is formed at a first preestablished temperature thereon with a first epitaxial thin film (2) made of a first material, e. g., BaTiO3, and then on the first epitaxial thin film (2) with a second epitaxial thin film (6) made of a second material, e. g., BaxSr1?xTiO3 (where 0<x<1), that contains a substance of the first material and another substance which together therewith is capable of forming a solid solution in a preestablished component ratio. Thereafter, the substrate is heat-treated at a second preselected temperature. Heat treated at the second preestablished temperature, the substrate has dislocations (4) introduced therein and the second epitaxial thin film (6) has its lattice constant relaxed to a value close to the lattice constant of bulk crystal of the second material.

Abstract: A method of adjusting the in-plane lattice constant of a substrate and an in-plane lattice constant adjusted substrate are provided. A crystalline substrate (1) made of SrTiO3 is formed at a first preestablished temperature thereon with a first epitaxial thin film (2) made of a first material, e. g., BaTiO3, and then on the first epitaxial thin film (2) with a second epitaxial thin film (6) made of a second material, e. g., BaxSr1-xTiO3 (where 0<x<1), that contains a substance of the first material and another substance which together therewith is capable of forming a solid solution in a preestablished component ratio. Thereafter, the substrate is heat-treated at a second preselected temperature. Heat treated at the second preestablished temperature, the substrate has dislocations (4) introduced therein and the second epitaxial thin film (6) has its lattice constant relaxed to a value close to the lattice constant of bulk crystal of the second material.