  We perform a systematic study on the surface property of nucleus-nucleus
potential in heavy-ion reactions using large-angle quasielastic scattering at
energies well below the Coulomb barrier. At these energies, the quasielastic
scattering can be well described by a single-channel potential model.
Exploiting this fact, we point out that systems which involve spherical nuclei
require the diffuseness parameter of around 0.60 fm in order to fit the
experimental data, while systems with a deformed target between 0.8 fm and 1.1
fm.
