Study On The Preparation Process Of The Buffer Layer GdBi03 By Chemical Solution Deposition

The aim of this dissertation is to study the chemical preparation approaches for the buffer layers.A new series of buffer layer materials of self intellectual properties have been proposed and rapid cost-effective approaches of preparation of high quality buffer layer have been developed based on polymer assistance.Several interesting results have thus been obtained by the optimization of the key thermal parameters during the preparation process.The results are useful and excited.In Chapter 1,the superconductivity and the superconducting materials have been reviewed,including the structure and the preparation approaches for the high temperature superconducting thin film,superconductivity and its basic phenomenon, history of superconductors,structure of high temperature superconductor,and substrate.In Chapter 2,the buffer layers have been reviewed.The main contents including: the study history of buffer layers,buffer layers for coated conductors(CCs),oxide buffer layer materials as wells as the novel buffer layer materials exploitation.In Chapter 3,the experimental methods as well as the characterization approaches concerned in this project has been discussed.The chemical solution deposition(CSD)approach has been introduced,means of the characterization for the phase structure,as well as surface properties have been provided.In Chapter 4,The details for preparation of GdBiO₃ thin film on single crystal substrate SrTiO₃ via polymer-assisted deposition route has been investigated.The key contents including:choice of substrate and raw materials,comparison of three different precursor solutions,coating and heat treatment process,the crystal structure of GBO and STO.A comparison between aqueous chemical solution deposition (CSD)and non-aqueous CSD approaches have been performed,indicating that GdBiO3 thin films with better quality have been obtained via the non-aqueous CSD approach.The non-aqueous approach shows the better stability.In Chapter 5,a systemic research on the influence of the key thermal parameters has been done.Including heating rate,annealing temperature and ambiance how to exert influence on the epitaxial growth of GBO film.By optimizing the decomposition and the phase formation procedure,GdBiO₃ thin film of thickness over 200 nm has been obtained.In Chapter 6,the structure of REBiO₃ has been showed.EuBiO₃,a typical REBiO₃,was deposited on STO successfully via aqueous CSD and non- aqueous CSD approaches.Eu_2-xBi_xO₃ films have been obtained on STO,providing a new approach to modify the lattice parameter of REBiO₃.The obtained results indicated that REBiO₃ may serve as a series of promising buffer layer materials.