Superconductivity in undoped T' cuprates with Tc over 30 K

Abstract

Undoped cuprates have long been considered to be antiferromagnetic insulators. In this article, however, we report that superconductivity is achieved in undoped T'-RE2CuO4 (RE = Pr, Nd, Sm, Eu, and Gd). Our discovery was performed by using metal-organic decomposition (MOD), an inexpensive and easy-to-implement thin-film process. The keys to prepare the superconducting films are firing with low partial-pressure of oxygen and reduction at low temperatures. The highest Tc of undoped T'-RE2CuO4 is over 30 K, substantially higher than "electron-doped" analogs. Remarkably, Gd2CuO4, even the derivatives of which have not shown superconductivity so far, gets superconducting with Tconset as high as ~ 20 K. The implication of our discovery is briefly discussed.

22 pages, 5 figures, submitted to Physical Review Letters

References in corpus (8)

• New class of T-prime-structure cuprate superconductors
• Superconductivity phase diagrams of electron doped cuprates R(2-x)CexCuO4 (R = La, Pr, Nd, Sm, and Eu)
• Kondo effect in underdoped n-type superconductors
• Hole superconductivity in the electron-doped superconductor PCCO
• Phase control of La2CuO4 in thin-film synthesis
• Superconductivity in undoped T'-RE2CuO4 with Tc over 30 K
• Role of impurity oxygen in superconductivity of "non-doped" T'-(La,RE)2CuO4
• Intrinsic electron-doping in nominal "non-doped" superconducting (La,Y)${}_2$CuO${}_4$ thin films grown by dc magnetron sputtering

Cited by in corpus (15)

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• Direct theoretical evidence for weaker correlations in electron-doped and Hg-based hole-doped cuprates
• Generic phase diagram of "electron-doped" T' cuprates
• Two-dimensional superconductor-insulator quantum phase transitions in an electron-doped cuprate
• New superconduting cuprates with no effective doping: T'-(La3+)2-x(RE3+)xCuO4
• Epitaxial engineering of flat silver fluorides cuprate analogs
• Reduction dependence of superconductivity in undoped T' cuprates
• Bulk superconductivity in undoped T'-La${}_{1.9}$Y${}_{0.1}$CuO${}_4$ probed by muon spin rotation
• Optical study of superconducting Pr${}_2$CuO${}_x$ with $x\simeq 4$
• Superconductivity induced by structural reorganization in the electron-doped cuprate Nd${}_{2-x}$Ce${}_x$CuO${}_4$
• Electron-Doping Effect on Tc in the Undoped (Ce-Free) Superconductor T'-La1.8Eu0.2CuO4 Studied by the Fluorine Substitution for Oxygen
• Tunable superconductivity in parent cuprate Pr${}_2$CuO${}_{4\pm \delta }$ thin films
• Eliashberg analysis of the optical conductivity in superconducting Pr${}_2$CuO${}_x$ ($x\simeq 4$)
• Electronic State of T'-Pr${}_{1.3-x}$La${}_{0.7}$Ce${}_x$CuO${}_4$ ($x=0.10$) Studied by Compton Scattering