  High precision angular distribution data of ($\alpha$,$\alpha$) elastic
scattering are presented for the nuclei $^{89}$Y, $^{92}$Mo,
$^{106,110,116}$Cd, $^{112,124}$Sn, and $^{144}$Sm at energies around the
Coulomb barrier. Such data with small experimental uncertainties over the full
angular range (20-170 degrees) are the indispensable prerequisite for the
extraction of local optical potentials and for the determination of the total
reaction cross section $\sigma_{\rm{reac}}$.
  A systematic fitting procedure was applied to the presented experimental
scattering data to obtain comprehensive local potential parameter sets which
are composed of a real folding potential and an imaginary potential of
Woods-Saxon surface type. The obtained potential parameters were used in turn
to construct a new systematic $\alpha$-nucleus potential with very few
parameters. Although this new potential cannot reproduce the angular
distributions with the same small deviations as the local potential, the new
potential is able to predict the total reaction cross sections for all cases
under study.
