Magnetic penetration depth of Pr1.85Ce0.15CuO4 and SM1.85Ce0.15CuO4 electron-doped superconductors

In this work, we report the temperature dependence of the lambda penetratio n depth, lambda (T) for Pr1.85Ce0.15CUO4 and SM1.85Ce0.15CUO4 electron-dope d superconductors. We have measured thin film samples of both compositions grown on STO substrates by using the pulsed laser deposition technique (PLD ). lambda (T) has been extracted by numerical analysis from the experimenta l mutual-inductance data obtained by using a home-made mutual-inductance br idge. We have found that they do not follow the conventional BCS behavior c haracteristic of other electron-doped superconductors like Nd1.89Ce0.15CuO4 and NbCN as recently reported. (C) 2001 Elsevier Science B.V. All rights r eserved.