| Summary: | 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.
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