  We report the impact of Ni doping on superconductivity of PdTe
superconductor. The superconducting parameters like critical temperature (Tc),
upper critical field (Hc2) and normalized specific-heat jump are reported for
Ni doped Pd1-xNixTe. The samples of series Pd1-xNixTe with nominal compositions
x=0, .01, 0.05, 0.07, 0.1, 0.15, 0.2, 0.3 and 1.0 are synthesized via solid
state reaction route. All the studied samples of series Pd1-xNixTe (x = 0.0 to
1.0) are crystallized in hexagonal crystal structure within the space group
P63/mmc. Unit cell volume shrinks almost linearly upon Ni doping in Pd1-xNixTe.
The normal state residual resistivity increases with Ni substitution on Pd
site. Both the electrical resistivity and magnetic measurements revealed that
Tc decreases with increase of Ni concentration in Pd1-xNixTe and is not
observed down to 2K for x=0.30 i.e., 30% of Ni doping at Pd site.
Interestingly, this is unusual for magnetic Ni doping in a known type-II BCS
type superconductor. Magnetic Ni must suppress the superconductivity much
faster. Interestingly, the isothermal magnetization measurements for NiTe
revealed that Ni is non-magnetic in Pd1-xNixTe structure and hence the Tc
depression is mainly due to disorder. The magneto-transport measurements
revealed that flux is better pinned for 20% Ni doped PdTe as compared to other
compositions of Pd1-xNixTe. The magnetic field dependence of specific heat of
Pd1-xNixTe for x=0.01 was studied and the estimated value of the normalized
specific-heat jump,is found to be 1.42, which is under BCS weak-coupling limit.
Summarily, we report the impact of Ni doping in Pd1-xNixTe superconductor and
conclude that Ni substitutes at Pd site, suppress superconductivity moderately
and is of non magnetic nature in this system. To best of our knowledge this is
the first study on Ni substitution in PdTe superconductor.
