Structural and electrical properties of c-axis oriented Y1-xCaxBa2(Cu1-yZny)3O7-delta thin films grown by pulsed laser deposition

TL;DR

This study investigates how Ca and Zn substitution, along with growth conditions, affect the structural and electrical properties of c-axis oriented YBCO thin films grown by pulsed laser deposition, revealing systematic variations in superconducting properties.

Contribution

It provides new insights into how Ca and Zn doping influence the orientation, resistivity, and superconducting transition temperature of YBCO thin films grown under controlled conditions.

Findings

Good c-axis orientation achieved at high deposition temperature

Overdoped samples with p ~ 0.195 identified

Systematic variation of Tc with Zn content

Abstract

Ca- and Zn-subsituted Y1-xCaxBa2(Cu1-yZny)O7-delta (x = 0, 0.05 and y = 0, 0.02, 0.04, 0.05) thin films were grown on SrTiO3 (100) substrates using the pulsed laser deposition (PLD) technique. Effects of various growth parameters on the quality of the film were studied via X-ray diffraction (XRD), atomic force microscopy (AFM), and in-plane resistivity, rhoab(T), measurements. The deposition temperature and oxygen partial pressure were gradually increased to 820C and 1.20 mbar respectively. Films grown under these conditions exhibited good c-axis orientation (primarily limited by the grain size) and low values of the extrapolated residual resistivity, rho(0), at zero temperature. The planar hole content, p, was determined from the room temperature thermopower, S[290K], measurements and the effects of oxygen annealing were also studied. Fully oxygenated samples were found to be overdoped with p ~ 0.195. The Superconducting transition temperature Tc(p), and rho(T,p) showed the expected systematic variations with changing Zn content.