Spatial distribution of Bose condensate in high-temperature superconductors, determined by emission M$ouml$ssbauer spectroscopy

Abstract

It has been shown that temperature dependences of the gravity centres of 67 Cu( 67 Zn) and 67 Ga( 67 Zn) emission Mössbauer spectra of Nd 1.85 Ce 0.15 CuO 4 , La 1.85 Sr 0.15 CuO 4 and Tl 2 Ba 2 Ca 2 CuO 8 superconductors are described by the second-order Doppler shift in the temperature range T > T c , and Bose condensation of Cooper pairs should be taken into account at T < T c (T c is the superconducting transition temperature). The spatial nonuniformity of the electron density created by the Bose condensate has been observed in La 1.85 Sr 0.15 CuO 4 .