Structural distortion in (La,Sr)2CuO4 cuprates: an insight using luminescence and EPR probes

We have demonstrated that Eu3+ luminescence can be successfully employed as a local probe to explore the microscopic symmetry of the cationic sites in the Sr2+-substituted lanthanum cuprate superconductor(s). It has been found that Sr2+ substitution in La1−xSrxCuO4 (x∼0.4) does not alter the microscopic symmetry of the cationic site(s). Further, using electron paramagnetic resonance spectroscopy we have demonstrated that the hole centers arising out of Sr2+ substitution are localized around Cu2+ site(s).