Growth and structural characterization of large superconducting crystals of
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- Columbia Univ., New York, NY (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., NY (United States)
Large crystals of (La-Ca-2126) with x = 0:10 and 0.15 have been grown and converted to bulk superconductors by high-pressure oxygen annealing. The superconducting transition temperature, Tc, is as high as 55 K; this can be raised to 60 K by post-annealing in air. Here we present structural and magnetic characterizations of these crystals using neutron scattering and muon spin rotation techniques. While the as-grown, non-superconducting crystals are single phase, we nd that the superconducting crystals contain 3 phases forming coherent domains stacked along the c axis: the dominant La-Ca-2126 phase, very thin (1.5 unit-cell) intergrowths of La2CuO4, and an antiferromagnetic La8Cu8O20 phase. We propose that the formation and segregation of the latter phases increases the Ca concentration of the La-Ca-2126, thus providing the hole-doping that supports superconductivity.
- Research Organization:
- Brookhaven National Laboratory (BNL), Upton, NY (United States); Energy Frontier Research Centers (EFRC) (United States). Center for Emergent Superconductivity (CES); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
- Grant/Contract Number:
- AC05-00OR22725; SC0012704
- OSTI ID:
- 1412763
- Report Number(s):
- BNL--114738-2017-JA; KC0201060
- Journal Information:
- Physical Review Materials, Journal Name: Physical Review Materials Journal Issue: 7 Vol. 1; ISSN PRMHAR; ISSN 2475-9953
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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