Magnetic ordering of Mn2GeS4 single crystals with olivine structure

Single crystals of Mn2GeS4 were grown by chemical vapor transport. X-ray powder diffraction data show a single phase. Rietveld refinement results indicated that Mn2GeS4 crystalize in an olivine-type structure. The magnetic properties of the compound have been studied by means of DC magnetometry and AC susceptibility measurements. The system shows two different phase transitions on decreasing temperature, a first one at about 90 K, leading the system from the paramagnetic to an antiferromagnetic state and a second at about 25 K, corresponding to the onset of a weak ferromagnetic behavior superimposed to the underlying antiferromagnetic order. No evidence of a possible spin-glass behavior in the intermediate temperature region has been found.