Giant peak effect observed in an ultrapure YBa2Cu3O6.993 crystal

Article

关键词: MELTING TRANSITION;    II SUPERCONDUCTORS;    SINGLE-CRYSTALS;    CRITICAL STATE;    VORTEX;    YBA2CU3O7-DELTA;    BAZRO3;    GROWTH;    LINE;   

DOI  :  10.1103/PhysRevB.60.R12593

来源: SCIE

【 摘 要 】

A giant peak in the temperature dependence of the screening current is observed in the ac magnetic response of an ultrapure YBa2Cu3O6.993 crystal in a magnetic field. At H = 2.0 T (H//c), the screening current density J(c)(T) exhibits a 35-fold rise with a 0.5 K increase in temperature, indicating an abrupt 10(3)-fold collapse in the characteristic volume of ordered regions in the vortex array. The peak-effect anomaly is most pronounced for H < 4.0 T, but detectable up to 7.0 T. The temperature dependence of the equilibrium magnetization exhibits a small discontinuous jump (for high fields) inside the peak-effect regime, suggesting that the underlying phase transition is a weak first-order vortex-lattice melting transition. [S0163-1829(99)51042-4].

【 授权许可】

Free