We discovered that the immiscibility between La1.85Sr 0.15CuO4 and Lu2Cu2O5 leads to a micrometer-scale heterogeneous mixture of a superconducting cuprate and an antiferromagnetic insulator. Whereas electronic conduction of the mixture in the normal state exhibits a percolation behavior, superconducting T c systematically increases with increasing amounts of insulating Lu2Cu2O5. The highest onset Tc of 46 K is achieved near the percolation threshold. Even though an unusual magnetic proximity effect cannot be ruled out, a plausible cause for the Tc enhancement is the tensile strain in highly anisotropic La1.85Sr 0.15CuO4 induced by the differential thermal contraction of the two phases.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2011 Jun 21|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics