The effect of Sb doping for Mn on structure, magnetic properties and magnetocaloric effect of Mn1−xSbxCoGe alloys

Abstract

The effect of Sb doping on the structure, magnetic properties and magnetocaloric effect of Mn1−xSbxCoGe (x = 0, 0.01, 0.02, 0.04, 0.06) alloys have been investigated. The doping of Sb for Mn results in the decrease of the structural transition temperature (Tt). For compound with x ≤ 0.01, the coupling of the magnetic and structural transitions occurs, leading to so called first-order magnetostructural transition (MST). Continually increasing x to 0.02 leads to decoupling of the magnetic and structural transitions. For $$x \geqslant 0.04$$ , an interesting phenomenon is appearance of single transition with ferromagnetic transition temperature (TC). For Mn0.99Sb0.01CoGe sample, the maximal value of the magnetic entropy change $$(\left| {\Delta {S_{\text{M}}}} \right|)$$ attains about $$17.7\,{\text{J}}/{\text{kg}}\,{\text{K}}$$ , and the refrigerant capacity (RC) can reach about 204 J/kg under a field change of 5 T. The small magnetic hysteresis, and large RC with MST near room temperature would make this alloy system prospectively put into use for room-temperature magnetic refrigeration materials.