Magnetic phase transition and magnetocaloric effect in Mn1?xZnxCoGe alloys

The magnetic phase transition and magnetocaloric effect are studied in a series of Mn1-xZnxCoGe (x = 0.01, 0.02, 0.04, and 0.08) alloys. By introducing a small quantity of Zn element, the structural transformation temperature of the MnCoGe alloy is greatly reduced and a first-order magnetostructural transition is observed. Further increasing the Zn concentration results in a second-order ferromagnetic transition. Large room-temperature magnetocaloric effects with small magnetic hysteresis are obtained in alloys with x = 0.01 and 0.02, which suggests their potential application in magnetic refrigeration.