Novel magnetic flux penetration in overdoped La2-xSrxCuO4 single crystals: macroscopic phase separation in a heavily overdoped regime
Abstract:Superconducting diamagnetic properties and magnetic flux penetration have been comparatively investigated on two La2-xSrxCuO4 single crystals: one underdoped (x 0.092) and the other overdoped (x 0.24). Both samples have only a single transition when the external field is low. While when a relatively high external field is applied, a large distinction between these two samples is observed: there is only one transition for the underdoped sample, but an unexpected second transition appears for the overdoped sample. Further investigation on the overdoped sample shows that it has a novel property of magnetic flux penetration, which is characterized by the vanishing of the usual central peak near zero field on the magnetization hysteresis loops. This easy penetration of magnetic flux can be understood in the picture of percolative superconductivity due to the inhomogeneous electronic state in a heavily overdoped regime.
Document Type: Miscellaneous
Publication date: January 1, 2002