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Magnetic signatures of 120 K superconductivity at interfaces in La2CuO4+δ.

Accepted version
Peer-reviewed

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Type

Article

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Authors

Choi, Eun-Mi 
Lu, Ping 
Sun, Xing 

Abstract

In self-assembled vertically aligned nanocomposite (VAN) thin films of La2CuO4+δ + LaCuO3, we find from DC magnetic susceptibility measurements, weak signatures of superconductivity at ∼120 K. This compares to a maximum TC of 40 K in bulk La2CuO4+δ. The 120 K signature occurs only when both c-axis and a-axis oriented La2CuO4+δ grains are present in the films. The superconductivity was lost after 3 months of storage but was recovered by annealing in oxygen. From lattice parameter analyses undertaken close to the c/a grain boundaries, it was determined that expansion of the La perovskite block in c-La2CuO4+δ enables the differently oriented grains to join at the interface. This expansion is consistent with the higher TC interfacial region. The work shows a new direction for increasing TC in cuprates - namely careful strain engineering of the crystal structure independently in-plane and out-of-plane.

Description

Keywords

51 Physical Sciences, 5104 Condensed Matter Physics

Journal Title

Nanoscale

Conference Name

Journal ISSN

2040-3364
2040-3372

Volume Title

12

Publisher

Royal Society of Chemistry (RSC)

Rights

All rights reserved
Sponsorship
Engineering and Physical Sciences Research Council (EP/N509620/1)
Isaac Newton Trust EPSRC (EP/N509620/1) China Scholarship Council Cambridge Commonwealth, European and International Trust U.S. National Science Foundation