LAUSR

ABSTRACT We present the study of a high T c superconductor under residual strain. We study the growth of a series of thin films of Y B a 2 C u 3 O 7 − δ (YBCO) using the Pulsed Laser Deposition (PLD) technique. The samples exhibit a residual in-plane compressive strain, whose degree depends on the growth conditions and the thickness of the film, and which alters the superconducting behavior. A thorough characterization of the system, correlating structural and superconducting properties is presented. Raman spectroscopy is introduced to characterize the samples and rule out oxygen loss effects. A possible explanation for the nearly linear depression of the critical temperature T c with c-axis expansion was introduced, in terms of the mutual Coulomb screening of charge fluctuations along the c-axis, between consecutive C u O 2 planes in the structure.