Interaction between a ferromagnet and a high-temperature superconductor at the interface in thin-film heterostructures

Abstract

The development of high-temperature superconductor (HTSC)/ferromagnet thin-film heterostructures is a promising direction in their application to spin-wave electronics. The state of the HTSC-ferromagnet interface determines the nature of the propagation of the surface magnetostatic waves in the heterostructure. The formation of the HTSC films in the heterostructures involves thermal treatment at high temperatures, which results in the diffusion interaction of the HTSC films and the ferromagnet. The heterostructure consists of a YBa₂Cu₃O_7−x HTSC film deposited by pyrolysis on an Y₃Fe₅O₁₂ ferromagnetic film grown epitaxially on a (111)-oriented gadolinum-gallium garnet Gd₃Ga₅O₁₂ substrate. The interdiffusion is studied from the intensity distribution curves of the x rays of iron (Fe), barium (Ba), copper (Cu), and silver (Ag), the last introduced into the HTSC in the amounts of 5–50 wt.%. The thin-film heterostructures are studied in the microwave range. A correlation is found between the state of the interface and the microwave characteristics.