Growth and structural characterization of large superconducting crystals of La2−xCa1+xCu2O6
| Autor: | Wei Tian, Ruidan Zhong, G. D. Gu, K. M. Mohanty, John M. Tranquada, Matthew B. Stone, Guangyong Xu, John Schneeloch, Zurab Guguchia |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Superconductivity
Materials science Physics and Astronomy (miscellaneous) Doping 02 engineering and technology Muon spin spectroscopy Neutron scattering Characterization (mathematics) 021001 nanoscience & nanotechnology 01 natural sciences Crystallography Condensed Matter::Superconductivity Phase (matter) 0103 physical sciences Antiferromagnetism General Materials Science 010306 general physics 0210 nano-technology Oxygen annealing |
| Zdroj: | Physical Review Materials. 1 |
| ISSN: | 2475-9953 |
| DOI: | 10.1103/physrevmaterials.1.074801 |
| Popis: | Large crystals of ${\mathrm{La}}_{2\ensuremath{-}x}{\mathrm{Ca}}_{1+x}{\mathrm{Cu}}_{2}{\mathrm{O}}_{6}$ (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, ${T}_{c}$, is as high as 55 K; this can be raised to 60 K by postannealing in air. Here we present structural and magnetic characterizations of these crystals using neutron scattering and muon spin rotation techniques. While the as-grown, nonsuperconducting crystals are single phase, we find that the superconducting crystals contain three phases forming coherent domains stacked along the $c$ axis: the dominant La-Ca-2126 phase, very thin (1.5 unit-cell) intergrowths of ${\mathrm{La}}_{2}{\mathrm{CuO}}_{4}$, and an antiferromagnetic ${\mathrm{La}}_{8}{\mathrm{Cu}}_{8}{\mathrm{O}}_{20}$ 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. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|