Magnetism and magnetocaloric effect of Mn0.98Fe0.02CoGe

The crystallographic and magnetic properties of Mn0.98Fe0.02CoGe have been investigated by X‐ray diffraction, dc magnetization and neutron diffraction over the temperature range 20–450 K. The temperature dependence of the phase fractions of the orthorhombic and hexagonal phases is described well by a Gaussian distribution. The Mn0.98Fe0.02CoGe sample exhibits a first‐order magneto‐structural transition centred at TMS ∼ 297 K of FWHM ∼37 K with a magnetic entropy change of −ΔSM = 24(1) J kg−1 K−1 for ΔB = 0–5 T. Neutron diffraction indicates a ferromagnetic orthorhombic structure below TMS with only the Mn carrying magnetic moment (3.98(6) µB) at 20 K. The sample is paramagnetic in the hexagonal phase above TMS.