  Motivated by the celebrated Schoen-Yau-Gromov-Lawson surgery theory on
metrics of positive scalar curvature, we construct a double manifold associated
with a minimal isoparametric hypersurface in the unit sphere. The resulting
double manifold carries a metric of positive scalar curvature and an
isoparametric foliation as well. To investigate the topology of the double
manifolds, we use K-theory and the representation of the Clifford algebra for
the FKM-type, and determine completely the isotropy subgroups of singular
orbits for homogeneous case.
