Evidence for Defect-Induced Superconductivity up to 49 K in (Ca₁₋ₓ)Fe₂As₂

dc.contributor.authorDeng, L. Z.en_US
dc.contributor.authorLv, Bingen_US
dc.contributor.authorZhao, K.en_US
dc.contributor.authorWei, F. Y.en_US
dc.contributor.authorXue, Y. Y.en_US
dc.contributor.authorWu, Z.en_US
dc.contributor.authorChu, C. W.en_US
dc.contributor.utdAuthorLv, Bingen_US
dc.date.accessioned2016-09-27T20:42:31Z
dc.date.available2016-09-27T20:42:31Z
dc.date.created2016-02-12en_US
dc.date.issued2016-02-12en_US
dc.description.abstractTo explore the origin of the unusual nonbulk superconductivity with a T_c up to 49 K reported in the rare-earth-doped CaFe₂As₂, the chemical composition, magnetization, specific heat, resistivity, and annealing effect are systematically investigated on nominal Ca₁₋ₓ Rₓ)Fe₂As₂ single crystals with different x and R = La, Ce, Pr, and Nd. All display a doping-independent T_c once superconductivity is induced, a doping-dependent low field superconducting volume fraction ʄ, and a large magnetic anisotropy η the superconducting state, suggesting a rather inhomogeneous superconducting state in an otherwise microscale homogenous superconductor. The wavelength dispersive spectroscopy and specific heat show the presence of defects that are closely related to ʄ, regardless of the R involved. The magnetism further reveals that the defects are mainly superparamagnetic clusters for R = Ce, Pr, and Nd with strong intercluster interactions, implying that defects are locally self-organized. Annealing at 500 ⁰C, without varying the doping level x, suppresses ʄ profoundly but not the T_c. The above observations provide evidence for the crucial role of defects in the occurrence of the unusually high T_c ~ to 49K in Ca₁₋ₓ Rₓ Fe₂As₂ and are consistent with the interface-enhanced superconductivity recently proposed.en_US
dc.description.sponsorshipUS Air Force Office of Scientific Research Grants No. FA9550-09-1-0656 and No. FA9550-15-1-0236.en_US
dc.identifier.bibliographicCitationDeng, L. Z., B. Lv, K. Zhao, F. Y. Wei, et al. 2016. "Evidence for defect-induced superconductivity up to 49 K in (Ca₁₋ₓ)Fe₂As₂" Physical Review B 93(5), doi:10.1103/PhysRevB.93.054513en_US
dc.identifier.issn2469-9950en_US
dc.identifier.issue5en_US
dc.identifier.urihttp://hdl.handle.net/10735.1/5089
dc.identifier.volume93en_US
dc.language.isoenen_US
dc.publisherAmer Physical Socen_US
dc.relation.urihttp://dx.doi.org/10.1103/PhysRevB.93.054513
dc.rights©2016 American Physical Societyen_US
dc.sourcePhysical Review B
dc.subjectCrystalsen_US
dc.subjectSuperconductorsen_US
dc.subjectSemiconductor dopingen_US
dc.subjectAnnealing of crystalsen_US
dc.subjectAnisotropyen_US
dc.titleEvidence for Defect-Induced Superconductivity up to 49 K in (Ca₁₋ₓ)Fe₂As₂en_US
dc.type.genreArticleen_US

Files

Original bundle

Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
NSM-4828-4528.44.pdf
Size:
1.11 MB
Format:
Adobe Portable Document Format
Description:
Article

License bundle

Now showing 1 - 1 of 1
No Thumbnail Available
Name:
American Physical Society.pdf
Size:
118.95 KB
Format:
Adobe Portable Document Format
Description:

Collections