Phase control of La2CuO4 in thin-film synthesis

Abstract

The lanthanum copper oxide, La2CuO4, which is an end member of the prototype high-Tc superconductors (La,Sr)2CuO4 and (La,Ba)2CuO4, crystallizes in the "K2NiF4" structure in high-temperature bulk synthesis. The crystal chemistry, however, predicts that La2CuO4 is at the borderline of the K2NiF4 stability and that it can crystallize in the Nd2CuO4 structure at low synthesis temperatures. In this article we demonstrate that low-temperature thin-film synthesis actually crystallizes La2CuO4 in the Nd2CuO4 structure. We also show that the phase control of "K2NiF4"-type La2CuO4 versus "Nd2CuO4"-type La2CuO4 can be achieved by varying the synthesis temperature and using different substrates.

4 pages, 5 figures, submitted to PRB, revtex

Cited by in corpus (11)

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• Role of impurity oxygen in superconductivity of "non-doped" T'-(La,RE)2CuO4
• Doping of Ce in T-La2CuO4: Rigorous test for electron-hole symmetry for high-Tc superconductivity
• Origin of superconducting carriers in "non-doped" T'- (La,RE)2CuO4 (RE = Sm, Eu, Gd, Tb, Lu, and Y) prepared by molecular beam epitaxy
• Charge transfer gap for T'-RE2CuO4 and T-La2CuO4 as estimated from Madelung potential calculations
• Intrinsic electron-doping in nominal "non-doped" superconducting (La,Y)${}_2$CuO${}_4$ thin films grown by dc magnetron sputtering
• Origin of superconductivity in nominally "undoped" T'-La${}_{2-x}$Y${}_x$CuO${}_4$ films
• Ce doping in T-La2CuO4 films: Broken electron-hole symmetry for high-Tc superconductivity