MOCVD of superconducting oxides, heterostructures and superlattices

Abstract
Superconducting YBa₂Cu₃O₇ thin films have been grown by Injection MOCVD on different kind of monocristalline substrates : MgO, NdGaO₃, LaAlO₃ with critical current densities Jc(77K) over 10⁶A/cm² on all of these substrates and up to 7.10⁶A/cm² on LaAlO₃. Heterostructures have been grown on metallic substrates with convenient YSZ buffer. Biaxially textured YBCO films have been realized with Jc(77K) = 5.10⁵A/cm². Other heterostructures with an active dielectric SrTiO₃ layer have been grown for tunable microwave devices applications with promising properties. Finally Injection MOCVD has shown to be well adapted for the formation of multilayers and superlattices with a control of the layer thickness in the range of one unit cell. YBa₂Cu₃O_7-δ/PrBa₂Cu₃O_7-δ superlattices have been grown with anisotropic superconducting properties which can be tailored by changing the layer thickness of both superconducting and insulating layer.