Single crystal growth and vortex matter phase diagram in HgBa2CuO4+x superconductor

In this work we report on the crystal growth process, the crystal structure and the phase diagram of HgBa2CuO4+x high Tc superconductor. Precise global DC magnetization measurements, using a SQUID magnetometer, have been performed, on two single crystals in magnetic fields parallel to the c-axis (H∥c) with Tc=95 and 89.9 K, respectively. The irreversibility curve Hirr(T) decreases exponentially up to a temperature T∗ and after it changes slope abruptly. The magnetization curves at a fixed temperature as a function of magnetic field show two peaks, namely Hfp(T) and Hsp(T).