Magnetic properties of the low-dimensional Ba M2Si2O7 system (M =Cu , Co , Mn )

We investigated the magnetic properties of the low-dimensional Ba M₂Si₂O₇ (M = Cu, Co, and Mn) system using both experimental measurements and theoretical calculations. Magnetization, specific heat, and single crystal neutron diffraction measurements have been performed on single crystal BaMn₂Si₂O₇ . The spin structure was determined and a magnetic phase diagram with applied field along the b axis was constructed, which contains a spin flop transition around 6 T. Magnetization and specific heat measurements confirmed the presence of weak ferromagnetism in BaCo₂Si₂O₇ . Furthermore, we performed local-spin density approximation with on-site Coulomb energy (LSDA +U ) calculations for the Ba M₂Si₂O₇ (M = Cu, Co, and Mn) system. Based on the first-principles calculations, the origin of the magnetic differences of the three materials is discussed.