Tuning of cu doping on phase transition and high-field phase diagram of Nd0.5Sr0.5Mn1−xCuxO3

Abstract

Pulsed high magnetic fields up to 52T have been used in the systematic investigation of the magnetic properties of manganites Nd0.5Sr0.5Mn1−xCuxO3 (0≤x≤0.15). The Cu-doping dependent first-order metamagnetic transitions are observed below the charge ordering temperature, which is ascribed to both Cu-doping and field-induced collapse of the charge ordering with antiferromagnetic phase. Based on the magnetization and electrical transport measurements, a three-dimensional phase diagram with coordinate axis of temperature, magnetic field, and doping level has been obtained, in which the critical fields of the metamagnetic transitions increase with the increase in Cu content and decrease with increasing temperature. The experimental results confirm that Mn-site substitution with Cu destroys the Mn3+–O2−–Mn4+ bridges and weakens the double exchange interaction between Mn3+ and Mn4+ ions, which shows an obvious tuning effect on the metamagnetic transition under the external magnetic field.