Improved biaxial texture of tri-layer YBCO/CaTiO3/YBCO films using an all chemical solution deposition method

•The tri-layer YBCO/CTO/YBCO film with the texture improvement was prepared by using an all chemical solution deposition method.•The effect of the CTO interlayer on the microstructure, texture and critical current density of YBCO thick films was discussed.•The reason that the JC was improved through the adoption of a heterostructure was investigated. The chemical solution deposition (CSD) is one of the most appealing routes for the growth of high-quality YBa2Cu3O7-δ (YBCO) films due to its advantages of low cost and high efficiency. However, as with other preparation methods such as pulsed laser deposition (PLD), the critical current densities (JC) of YBCO films prepared by the CSD method also dramatically decrease with increasing film thickness, which is known as thickness effect. In this paper, the tri-layer YBCO/CTO/YBCO thick films were deposited on buffered Hastelloy C276 tapes by using a dip coater based on all CSD method. By means of the introduction of the CTO interlayer, the JC reduction with increasing film thickness was inhibited, arising from the improvement of the biaxial texture in the tri-layer thick film. The JC value (77 K, self-field) of the tri-layer film was around 3.3 MA/cm2. The texture improvement was mainly ascribed to the interface levelling through the deposition of the CTO interlayer which is a template with good biaxial texture for the epitaxial growth of YBCO film.