Specific heat, magnetic properties and critical behaviour of Mn2SiS4 and Fe2GeS4

The hydrothermal synthesis and characterization of olivines and related compounds for electrochemical applications

“…The weak ferromagnetic state is not new for the olivine family. [41][42][43]. It is interesting to note that weak ferromagnetism was found in LiMnPO 4 samples by Arcon et al [36,44].…”

The Magnetic Structure of Mn2GeSe4

“…They were initiated by the surprising observation of a sharp local 1/χ minimum between 83 and 85 K for Mn 2 SiS 4 [2,3,4] accompanied by the occurrence of "weak ferromagnetism". This effect might be related to "metamagnetism" occurring in certain antiferromagnetic compounds under special conditions as a function of an external field (see, for example, ref.…”

“…The Mn 2+ ions in Mn 2 SiSe 4 show an antiferromagnetic ordering (easy direction: [001]). A complex behaviour with respect to the temperature dependence of susceptibility and magnetization was discussed on the basis of several measurements in two independent publications for the olivine type Fe 2 GeS 4 (T N = 144 K) [3,8] . This compound shows an antiferromagnetic ordering below 144 K (easy direction [010]) followed by a change of the easy direction to [001] at lower temperatures.…”

Anomalous Magnetic Properties Near the Spin-Flop Bicritical Point inMn2AS4(A=Siand Ge)

“…When we extrapolate the first-order line in the natural manner, we notice that it meets the H 0 line at a certain temperature T 0 ( 83:5 K), where the magnetic structure is expected to change from C y ÿ C 0 y to C x ÿ C 0 x with increasing T. Because each arrangement belongs to the different irreducible representation (ÿ 1g and ÿ 2g , respectively), the transition at T 0 should be first order. This kind of spinreorientation transition is observed in Fe 2 GeS 4 [12,13], where the spins reorient from the b to the a axis with decreasing T. To find the signature of such successive phase transition, we carried out the specific heat measurements. As seen in Fig.…”