Structural and magnetic properties of MnCo1-xVxGe compounds

The structural and magnetic properties of MnCo1-xVxGe (x = 0.00, 0.02, 0.04, 0.06, 0.08, 0.10, 0.20 and 0.30) compounds were investigated by means of X-ray diffraction, scanning electron microscopy and magnetization measurements. The MnCo1-xVxGe compounds crystallize in the orthorhombic TiNiSi-type crystal structure for x ≤ 0.02 and in the hexagonal Ni2In-type structure for x > 0.02. The magnetization measurements show that the MnCo1-xVxGe compounds exhibit a complex magnetic behavior. The Curie temperature can be tuned from 360 K to 148 K by increasing x. The maximal magnetic-entropy change is 3.9 J/kg K for x = 0.06 at a field change from 0 to 1.5 T at about 265 K.