Magnetization study of (Hg,Cr)Sr2CuO4+delta superconductor

(Hg,Cr)-Sr-1201 type superconductor of nominal composition Hg0.7Cr0.3Sr2CuO 4+delta was synthesized by the sealed quartz-tube method. X-ray diffraction analysis of the sample showed it has tetragonal symmetry with lattice para meters a = 3.841(1) Angstrom, and c = 8.664(3) Angstrom. The as-prepared sa mple is superconducting at 60 K as shown by dc-magnetization and dc-resisti vity measurements, The irreversibility line (IL) obtained from the merging point of the zero-field-cooled and the field-cooled magnetization measureme nts at several applied fields was found to obey the equation H = A(1 - T/T- c)(n) and gave a value of 2.55 for the exponent "n." Using magnetic hystere sis loops the critical current density of superconducting (Hg,Cr)-Sr-1201 w as estimated. The irreversibility line and magnetic hysteresis showed reduc ed pinning properties of (Hg,Cr)-Sr-1201 as compared to HgBa2CuO4+delta.