Our recent experimental works on the inhomogeneity of superconductivity in both underdoped and overdoped regimes of La2-xSrxCuO 4 are reviewed. In order to estimate the superconducting (SC) volume fraction in a sample, bulk-sensitive magnetic-susceptibility and specific-heat measurements have been carried out, using La2-xSrxCuO 4 single crystals of good quality with x 0.05-0.3. As a result, it has been found that the SC volume fraction is not 100% in both underdoped and overdoped regimes, suggesting the occurrence of a phase separation into SC and non-SC regions. Moreover, strong vortex-pinning effects have been observed in moderate magnetic fields in the overdoped regime, suggesting that the phase separation in the overdoped regime is not macroscopic but microscopic.
ASJC Scopus subject areas
- Physics and Astronomy(all)