The pressure effect of YBa2Cu3O7-δhigh temperature superconduc- ting film grown on BaTiO3 piezoelectric substrate.

• Main Authors: Lin,Chyi-Hrong, 林奇鴻
• Other Authors: H. Chou
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/06035009041716931551

碩士 === 國立中山大學 === 物理研究所 === 84 === Since HTSCs was discovered in 1986 , the influence of external pressure on high temperature superconductors is one of the important topic in HTSCs research . In earlier studies , people introduced hydropressure on the sample which changed the lengths of unit cell in all axes. Therefore, all effects associated with individual axes are involved that make phenomena very complicate. The main goal of this project is to study the possible of imposing uniaxial pressure on the superconductor of YBa2Cu3O7-δ high temperature superconducting films . To understand other physical effects, besides the charge redistribution effect on the CuO2 which is believed to be the main contribution by the applied pressure plane ,may cause the change of superconductor. In this project, epitaxial films were grown on piezoelectric single crystal substrates BaTiO3 . The uniaxial pressure applied along the film is generated by applying a high electric field along the surface of substrate. With this external electric field , the piezoelectric substrate will undergo an extension or contraction that produces a strain along the surface ofa-b plane of the films . The normal state resistivity , superconducting transition temperature (Tc) under the influence e will be measured. In the first part of this thesis, we study the relationship between the polarizing of substrates and the polishing of substrates . Studies are also focusing in the mechanical pressure and the electric field to the polarization of BaTiO3 substrate.To understand the film properties to roughness of the substrate. The second part is the experiment concerning the phase transformation of BaTiO3 to the superconductivity of the film.