Using single crystal neutron diffraction, we studied the H (∥ b) - T phase diagram of the antiferromagnetic olivine Mn2 AS4 (A = Si, Ge). We identified the two spin-flop phases at high fields that are separated by field-independent phase boundaries terminated at multicritical points. In the low temperature phase, the magnetic structures consist of antiferromagnetic Cz - Cz ′ and ferromagnetic Fx ′ components. In the high temperature phase, in contrast, they are replaced by Cx - Cx ′ and Fz ′. The absence of the anomalies in the DC magnetization data across the spin-reorientation transitions is discussed in terms of the Clausius-Clapeyron relation.
- Magnetic phase diagram
- Neutron scattering
ASJC Scopus subject areas
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials