Pulsed-laser deposition of metastable Ca1-xSrxCuO2 thin films

One of the more interesting copper oxide materials is the tetragonal phase of Ca1-xSrxCuO2, as it can be viewed as the parent structure of all of the ''high Tc'' superconducting cuprates. Although simple in structure, this copper oxide is metastable, requiring high pressures and temperatures for bulk synthesis. However, recent efforts have shown that formation of this phase can be achieved as an epitaxial thin film at low oxygen pressures (1-200 mTorr) and temperatures (450-700 degree C) by pulsed laser deposition. We will discuss the growth of Ca1-xSrxCuO2 by pulsed laser deposition, and the effects of various growth conditions on the transport and structural properties of these films. In particular, we will show that conductivity in this material can be significantly improved at the Sr-rich end of the solid solution. In addition, we will discuss the effect of alkaline-earth (Sr,Ca) vacancies on the transport properties of these thin films, and discuss anomalies observed in the resistivity of these metastable thin film structures