  Metal thio(seleno)phosphates MPX$_3$ have attracted considerable attentions
with wide spanned band gaps and rich magnetic properties. In this series, two
neighboring members MnPS$_3$ and NiPS$_3$ differ in magnetic atoms, magnetic
easy axes, spin anisotropy, as well as nearest-neighbor magnetic interactions.
The competition between these components may cause intriguing physical
phenomena. In this article, the evolution of magnetism of
Mn$_{1-x}$Ni$_x$PS$_3$ series is reported. Despite the incompatible
antiferromagnetic orders of two end members, the antiferromagnetism persists as
the ground state in the whole substitution region. The magnetic ordering
temperature $T_{\rm N}$ show nonmonotonic V-shape behavior, and the reentrant
spin glass phase at x=0.5 is observed. In addition, abnormal bifurcation of
$T_{\rm N}$ occurs at x=0.75, which may be due to the temperature-dependent
spin reorientation or phase separation. The evolution of magnetism is further
confirmed semi-quantitatively by our density functional theory calculations.
Our study indicates that exotic magnetism can be intrigued when multi-degrees
of freedom are involved in these low-dimensional systems, which call for more
in-depth microscopic studies in future.
