Differences of the magnetic hysteresis behaviors in the magnetostructural transformation Mn1−xVxCoGe alloys

• The average magnetic hysteresis losses upon cooling are much larger than that upon heating for Mn1−xVxCoGe alloys.
• The origin for the discrepancy of magnetic hysteresis is discussed.
• The effects of the discrepancy of magnetic hysteresis on the magnetocaloric properties are investigated for Mn1−xVxCoGe alloys.

The magnetic hysteresis behaviors and the magnetocaloric properties of the Mn1−xVxCoGe (x=0.01 and 0.02) alloys in the heating and cooling runs have been investigated comparatively in the vicinity of the first-order magnetostructural phase transition. The magnetic hysteresis behaviors reveal an evident discrepancy between the heating and cooling processes. The average hysteresis losses estimated from the initial magnetization isotherms M(H) measured upon cooling are much larger than that upon heating. Considering the thermodynamics conditions and the potential barrier of phase transition, we analyzed the possible origin for this discrepancy and discussed the effects on the magnetocaloric properties for these two alloys.