La16xd04SrxCuO4超导体的磁性和输运性质与条纹相的关系.docx

Abstract ABSTRACT The charge inhomogeneity is one of the intrinsic properties in the doped Mott antiferromagnets．For the high temperature superconductors，charge stripe has been observed by many experiments．In a stripe phase，the doped carriers accommodate in striped pattem and separate the antiferromagnetic domains in the Cu02 plane．It is believed that the charge and spin stripes are closely related to the high temperature superconductivity． In this dissertation．the anisotropic susceptibilities were studied in the Lal．6-烈do．4SrxCu04 single crystals with static charge and spin stripes．The influence of stripe order on the vortex pinning and motion，and the relation between the charge transport and spin order were discussed．Furthermore，the intrinsic Josephson junction behavior in the stripe ordered superconductor was studied through the current-voltage 弘功characteristics along the c—axis． In chapter one，the picture and experiment evidences of the stripe phase were introduced．The relation between the stripe phase and superconductivity Was discussed．The pseudogap in the stripe ordered superconductor and the effect of magnetic field on the spin order were also introduced． In chapter two，the crystal growth process by optical floating—zone single crystal furnace was firstly introduced．Then，the dc and ac susceptibilities of the stripe．ordered Lal．6．xNdo．4SrxCu04 single crystals were studied under different magnetic field orientations．A particular two dimensional(2D)superconductivity, which is closely related to the decoupling between Cu02 planes caused by static stripe phase，was found．This 2D superconductivity rising at a temperature higher than the bulk疋suggests that the decoupling is one of the most important facts for the suppression of疋by static stripe phase． In chapter three，the angular dependencies of the ac susceptibility and dc magnetic relaxation of a stripe．ordered Lal．4sNd0．4Sro．1 5Cu04 single crystal were studied below the superconducting transition temperature死．