  The alpha and cluster decay properties of the $132-138$^Nd, $144-158$^Gd,
$176-196$^Hg and $192-198$^Pb even-even isotopes in the two mass regions A =
130-158 and A = 180-198 are analysed using the Coulomb and Proximity Potential
Model. On examining the clusters at corresponding points in the cold valleys
(points with same A_2) of the various isotopes of a particular nucleus we find
that at certain mass numbers of the parent nuclei, the clusters emitted are
getting shifted to the next lower atomic number. It is interesting to see that
the change in clusters appears at those isotopes where a change in shape is
occurring correspondingly. Such a change of clusters with shape change is
studied for the first time in cluster decay. The alpha decay half lives of
these nuclei are computed and these are compared with the available
experimental alpha decay data. It is seen that the two are in good agreement.
On making a comparison of the alpha half lives of the normal deformed and super
deformed nuclei, it can be seen that the normal deformed $132$^Nd, $176-188$^Hg
and $192$^Pb nuclei are found to be better alpha emitters than the super
deformed (in excited state) $134,136$^Nd, $190-196$^Hg and $194$^Pb nuclei. The
cluster decay studies reveal that as the atomic number of the parent nuclei
increases the N \neq Z cluster emissions become equally or more probable than
the N=Z emissions. On the whole the alpha and cluster emissions are more
probable from the parents in the heavier mass region (A=180-198) than from the
parents in the lighter mass region (A= 130-158). The effect of quadrupole
({\beta}_2) and hexadecapole ({\beta}_4) deformations of parent and fragments
on half life times are also studied.
