Ferroelectric field effect in ultrathin SrRuO3 films

We report the observation of a ferroelectric held effect in the conducting oxide SrRuO3 using Pb(Zr0.52Ti0.48) O-3/SrRuO3 epitaxial heterostructures. Upon reversing the polarization of the ferroelectric Pb(Zr0.52Ti0.48)O-3 layer, we measured a 9% change in the resistance of a nominally 30 Angstrom SrRuO3 him at room temperature. This change was nonvolatile for a period of several days. Conductivity measurements taken between 4.2 and 300 K are consistent with n-type conduction throughout this temperature range. Hall effect measurements also yield n-type conduction, with n approximate to 2 x 10(22) electrons/cm(3), and furthermore allow us to understand quantitatively the magnitude of the observed resistivity change. (C) 1997 American Institute of Physics.