Metal/ferroelectric/superconductor field effect transistor using Pb(Zr0.52Ti0.48)O-3/(Y0.6Pr0.4)Ba2Cu3O7-y heterostructures

Metal (Al,Ag,Au)/ferroelectric (Pb(Zr0.52Ti0.48)O-3 [PZT])/high-T-c superco nductor ((Y1-x Pr-x)Ba2CU3O7-y [YPBCO]) structures have been fabricated by ArF excimer laser deposition. Ferroelectric properties of c-axis oriented e pitaxial PZT films on YBa2Cu3O7-y [YBCO]//SrTiO(3)3(100) have been studied as a function of temperature in the range of 20-290 K. Samples with three k inds of metal electrode show almost similar ferroelectric properties at 290 K. The remanent polarization and coercive field are about 25 mu C/cm(2) an d 146 kV/cm, respectively. At low temperature, on the contrary,the ferroele ctric properties of heterostructures were strongly influenced by the choice of the electrode metal. It seems that these properties are severely affect ed by interface slates of metal PZT. The Au electrode gives rise to the bes t ferroelectric property of PZT films. We also investigated the ferroelectr ic field effect in the heterostructures of Au/ PZT/(Y0.6Pr0.4)Ba2Cu3O7-y. A large modulation (as much as similar to 40%) and memory effects are observ ed in the low frequency source-drain current response to a pulsed voltage. (C) 1999 Elsevier Science Ltd. All rights reserved.