Magnetic properties of the low-dimensional BaM2Si2O7 system (M=Cu, Co, Mn)

Abstract

We investigated the magnetic properties of the low-dimensional $\mathrm{Ba}{M}_{2}{\mathrm{Si}}_{2}{\mathrm{O}}_{7}$ ($M$ = 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 ${\mathrm{BaMn}}_{2}{\mathrm{Si}}_{2}{\mathrm{O}}_{7}$. 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 ${\mathrm{BaCo}}_{2}{\mathrm{Si}}_{2}{\mathrm{O}}_{7}$. Furthermore, we performed local-spin density approximation with on-site Coulomb energy ($\mathrm{LSDA}+U$) calculations for the $\mathrm{Ba}{M}_{2}{\mathrm{Si}}_{2}{\mathrm{O}}_{7}$ ($M$ = Cu, Co, and Mn) system. Based on the first-principles calculations, the origin of the magnetic differences of the three materials is discussed.