E.A. Stepantsov ‒ Ph.D. (Phys.-Math.), Leader Research Scientist, Federal Scientific-Research Center «Crystallography and Photonics» of RAR (Moscow)
It was studied the possibility of growth of high-Tc superconducting thin films YBa2Cu3O7 with large tilt to surface of basis planes on MgO substrates, which are characterized by high transparency for microwave radiation including terahertz diapason. The tilt was fulfilled by rotation of crystalline lattice of the film relatively the surface around  axis, which was oriented parallel to the surface. Necessary substrates have been fabricated in order to solve this task. Surfaces of them created different angles with (100) plane, starting from 0º and up to 70º with 5º steps, as a result of rotation of its crystalline lattice around  axis, which was parallel to the surface. Growth of the films was made by laser ablation technique from ceramic target of stehiometric composition. Nucleating sublayer from SrTiO3 was deposited on the substrate surface with the thickness less than a size of elementary cell by the same method just before that. Structure of the grown films was investigated with help of X-ray diffractometries by three dimensional scanning at rotation of a substrate with a film around of a perpendicular to their surface. It was found out that at tilt of basis plane of the films to their surfaces up to 41º the films were stay single crystalline. At higher angles they became two-domain like with gradual increasing of total square domains of new orientation. At the same time roughness of the films sharply increased. The results indicate about significant increasing of a field of crystallographic orientations at growth of single-crystalline high-Tc superconducting films YBa2Cu3O7 on substrates, which are transparent for microwave radiation up to terahertz diapason. In its turn it opens perspectives of significant increasing of a diapason of parameters of microwave devices of cryogenic electronics on the base of such films.
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