Magnetic properties of the quasi-one-dimensional S=1 spin chain antiferromagnet BaNiTe2O7

We report a quasi-one-dimensional $S=1$ spin chain compound $\mathrm{BaNi}{\mathrm{Te}}_{2}{\mathrm{O}}_{7}$. This magnetic system has been investigated by magnetic susceptibility, specific heat, and neutron powder diffraction. These results indicate that $\mathrm{BaNi}{\mathrm{Te}}_{2}{\mathrm{O}}_{7}$ develops a short-range magnetic correlation around $T\ensuremath{\sim}22\phantom{\rule{0.16em}{0ex}}\mathrm{K}$. With further cooling, an antiferromagnetic phase transition is observed at ${T}_{\mathrm{N}}\ensuremath{\sim}5.4\phantom{\rule{0.16em}{0ex}}\mathrm{K}$. Neutron powder diffraction revealed antiferromagnetic noncollinear order with a commensurate propagation vector $\mathbf{k}=(1/2,1,0)$. The refined magnetic moment size of ${\mathrm{Ni}}^{2+}$ at 1.5 K is $1.84{\ensuremath{\mu}}_{\mathrm{B}}$, and its noncollinear spin texture is confirmed by first-principles calculations. Inelastic neutron-scattering results and density functional theory calculations confirmed the quasi-one-dimensional nature of the spin systems.