BaCu02)m./CaSrCuO2n superlattices grown by pulsed laser deposition: structural and electrical transport properties

摘要

Abstract: In this paper we show that (BaCuO$-2$/)$-m$//((Ca,Sr)CuO$- 2$/)$-n$/ superlattices with good crystallographic quality can be engineered by Pulsed Laser Deposition in a wide range of composition, namely for m $EQ 2 and n ranging form 1 to 6. The temperature dependence of resistivity of the superlattices grown at relatively high oxygen pressure and temperatures above 570 degrees C is metallic with a full transition to a superconductive state. For optimized growth conditions, the critical temperature can reach a value of about 80 K. We investigated some of the electrical transport properties of these superlattices. The result of these measurements indicate, for these artificial structures, an intermediate degree of anisotropy between the highly anisotropic BSCCO and the relatively isotropic YBCO. Moreover, the dependence of T$-c$/ on the number of CaCuO$- 2$/ layers was investigated and a maximum was found for n $EQ 2-3. !16