  We report the results of magnetization, non-linear dc susceptibility,
electrical transport, and heat capacity measurements on Y-substituted heavy
fermion CeNiGe2. Investigations are carried out on the compounds CeNiGe2,
Ce0.9Y0.1NiGe2, Ce0.8Y0.2NiGe2 and Ce0.6Y0.4NiGe2. It is observed that with the
increase in Y-concentration, the magnetic ordering temperature decreases. For
CeNiGe2, below ordering temperature Arrott plots suggest the presence of spin
density wave (SDW). Third and fifth order dc susceptibility indicates magnetic
instability which possibly leads to partial gap opening resulting in the
observation of SDW. These observations are further investigated through
resistivity and heat capacity measurements which also point toward partial gap
opening in CeNiGe2. Interestingly, with the increase in Y-substitution, it is
noted that the gap opening is suppressed and also shifted towards lower
temperature. Moreover, our investigations reveal absence of non-Fermi liquid
behavior or zero field quantum critical point even after 40% dilution of
Ce-site.
