TEM investigation of the LZO sol gel system

To achieve an affordable and fast synthesis proces for coated conductors, chemical solution deposition (CSD) methods seem to be a sensible solution. Buffer layers and superconducting layers can be prepared by CSD. In this research, a water-based CSD method, based on metal acetates and triethanolamine as cpmlexing agent was applied to make La2Zr2O7 buffer layers. In this study, an optimal heat treatment was examined for layers between 30 and 150 nm, where parameters such as heating ramp, dwell time and dwell temperature were investigated on their influence on crystal orientation, surface roughness and microstructure. Slower heating is necessary to prevent the thick layers from pulverisation. Furthermore, heat rate and sinter temperature needed to be controlled to prevent the (111) orientation from growing. The crystal orientation was analysed by XRD, pole figures and RHEED. Surface roughness was measured by AFM. Microstructural analysis was carried out by TEM analysis. The orientation relation between the NiW substrate and LZO layer was not straightforward and was previously reported by Molina et al. [1]. A possible explanation for the aparent misalignment was proposed.