MOCVD of superconducting oxides, heterostructures and superlattices

Superconducting YBa2Cu3O7 thin films have been grown by Injection MOCVD on different kind of monocrystalline 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. YBa2Cu3O7-δ/PrBa2Cu3O7-δ superlattices have been grown with anisotropic superconducting properties which can be tailored by changing the layer thickness of both superconducting and insulating layer. (orig.)