The influence of the Landau-Zener effect on the fine structure of the
cluster decay phenomenon is evidenced. Estimations of hindrance factor
s are reported for the C-14 emission from Ra-223. The half-lives are c
alculated considering the cluster decay as a superasymmetric fission p
rocess appealing to the Wentzel-Kramers-Brillouin penetrabilities. The
excitation of the last unpaired nucleon is considered to be due mainl
y to the Landau-Zener promotion mechanism. The deformation energy is c
omputed in the framework Yukawa-plus-exponential model extended for bi
nary systems with different charge densities and adding the specializa
tion energy of the unpaired nucleon. The Werner-Wheeler approximation
is used to compute the effective mass. Assuming molecular states durin
g the disintegration, the superasymmetric two-center shell model is us
ed to obtain the level scheme of the cluster decay. [S0556-2813(98)062
05-0].