THERMOELECTRIC AND THERMOMAGNETIC EFFECTS IN ND1.85CE0.15CUOX EPITAXIAL THIN-FILMS

Epitaxial, c-axis oriented Nd1.85Ce0.15CuOx thin films have been fabri cated on (100) SrTiO3 substrates by hollow cathode magnetron sputterin g. The mixed state of the films has been characterized by measuring th e longitudinal resistivity and Nernst effect in magnetic fields up to 6T applied parallel to the c-axis. From the resistivity data an upper critical field slope dH(c2)/dT = -0.35T/K was obtained for films with T-c similar or equal to 22 K corresponding to an ab-plane coherence le ngth xi(ab) = 79 Angstrom. From the Nernst effect data the temperature derivative of the transport energy of magnetic flux lines was derived to dU(phi)/dT = -2.4 x 10(-13) J/Km. At T = 18K and H = 0.5T the tran sport entropy of magnetic flux lines was obtained to S-phi = 1.6 x 10( -14) J/Km. These values are in reasonable agreement with the predictio n of time dependent Ginzburg-Landau theory. The measured data are comp ared to those obtained for epitaxial YBa2Cu3O7-delta and Bi2Sr2CaCU2O8 +x thin films.