Magnetic/structural phase diagram and enhanced giant magnetoresistance in Zn-doped antiperovskite compound Ga1−xZnxCMn3

The structural, magnetic and electrical transport properties of Zn-doped antiperovskite compounds Ga1−xZnxCMn3 (0≤x≤0.30) have been investigated. After partial substitution of Zn for Ga, the Curie temperature increases monotonously and the ground antiferromagnetic (AFM)-ferromagnetic intermediate (FI) phase transition is gradually suppressed. With increasing the doping level x, the saturated magnetizations decreases gradually firstly for x≤0.20, then increases with increasing x. The electrical transport properties of Ga1−xZnxCMn3 are studied at different magnetic fields. Enhanced giant magnetoresistance (GMR) was observed around the AFM-FI transition. With increasing x, the maximal values and peak widths of GMR increase. Particularly, for x=0.20, GMR reaches a maximum value of 75%, spanning a temperature range of 80 K at 50 kOe and displays the behavior of strongly depending on the magnetization history. The possible origins are discussed.

► We studied the structural, magnetic and electrical transport properties of Zn-doped antiperovskite compounds Ga1−xZnxCMn3
► Enhanced GMR is observed around the antiferromagnetic-ferromagnetic intermediate phase transition.
► Maximal value and peak widths of MR increase quickly by increasing the doping level x.
► More interestingly, for x=0.20, MR could reach a maximum value of 75%, spanning a temperature range of 80 K at 50 kOe.