Resistivity onset at the first-order vortex-lattice phase transition in Bi2Sr2CaCu2O8

Simultaneous measurements of resistivity and local magnetization using microscopic Hall sensors were carried out on Bi2Sr2CaCu2O8 (BSCCO) crystals as a function of applied field and temperature. The resistivity onset is found to occur concurrently with the first-order vortex-lattice phase transition, determined by the equilibrium magnetization step. This behavior is indicative of a vortex-lattice melting transition. The resistivity vanishes below the transition although the magnetization remains reversible.