  IrTe$_2$ with large spin-orbital coupling (SOC) shows a CDW-like first order
structural phase transition from high-temperature trigonal phase to
low-temperature monoclinic phase at 270 K, accompanying with a large jump in
transport and magnetic measurement as well as in heat capacity. Here, the 3d
element Ni has been doped into IrTe$_2$ by growing Ir$_{1-x}$Ni$_x$Te$_2$
single crystals. Both XRD and XPS results reveal that the Ni atoms have
substituted for Ir, which is consistent with the calculation result. Like the
CDW behaviour, the structural phase transition shows competition and
coexistence with the superconductivity. The monoclinic phase transition has
been suppressed gradually with the increase of the doping amount of Ni, at last
giving rise to the stabilization of the trigonal phase with superconductivity.
Within 0.1$\leq$x$\leq$0.2, Ir$_{1-x}$Ni$_x$Te$_2$ shows the superconductive
behaviour with T$_c$ around 2.6K. The superconductivity shows anisotropy with
dimensionless anisotropy parameter $\gamma$=$\xi_{//}$$/$$\xi_{\perp}$$\sim$ 2.
Even Ni element shows ferromagnetic behaviour, Ir$_{1-x}$Ni$_x$Te$_2$ only
shows weak paramagnetism, no ferromagnetic order is observed in it, which is
coincident with the calculation result that their up and down spin density of
states compensate each other well. In addition, for other 3d elements Fe, Co
and Mn doped IrTe$_2$, only Ir$_{1-x}$Mn$_x$Te$_2$ owns magnetism with magnetic
moment of 3.0$\mu$$_B$ to the supercell, theoretically.
