title: Magnetic penetration depth measurements of Pr2-xCexCuO4-delta films on buffered substrates: evidence for a nodeless gap.
abstract: We report measurements of the inverse squared magnetic penetration depth, lambda(-2)(T), in Pr(2-x)Ce(x)CuO(4-delta) (0.115< or =x < or =0.152) superconducting films grown on SrTiO3 (001) substrates coated with a buffer layer of insulating Pr2CuO4. lambda(-2)(0), T(c), and normal-state resistivities of these films indicate that they are clean and homogeneous. Over a wide range of Ce doping, 0.124< or =x < or =0.144, lambda(-2)(T) at low T is flat: it changes by less than 0.15% over a factor of 3 change in T, indicating a gap in the superconducting density of states. Fits to the first 5% decrease in lambda(-2)(T) produce values of the minimum superconducting gap in the range of 0.29< or =Delta(min)/k(B)T(c)< or =1.01.
authors.affiliation: Department of Physics, The Ohio State University, Columbus, OH 43210-1106, USA.
authors.forename: Mun-Seog
authors.initials: MS
authors.lastname: Kim
authors.forename: John A
authors.initials: JA
authors.lastname: Skinta
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Lemberger
authors.forename: A
authors.initials: A
authors.lastname: Tsukada
authors.forename: M
authors.initials: M
authors.lastname: Naito