The growth and conductivity of CaCuO2 epitaxial thin films

Growth, structure and conductivity of epitaxial thin films of CaCuO2 (CCO) on SrTiO3, LaAlO3 and NdGaO3 substrates were investigated. The films were deposited by pulsed laser ablation from a single stoichiometric target at a pressure of 0.3 mbar and temperatures higher than 700 degreesC. X-ray diffraction reveals that films on (1 1 0)NdGaO3 substrates are single crystals of high quality without twinning and with extremely narrow (less then 0.05degrees) rocking curves. An expansion of the c-axis lattice constant is observed as Sr replaces Ca in CCO films. Transport measurements show that CCO films have a hopping conductivity for all films deposited on all the substrates with a resistivity within the range 10(-1)-10(4) Omega cm. (C) 2004 Elsevier B.V. All rights reserved.