  We present radio and X-ray studies of A3444 and MS1455.0+2232, two galaxy
clusters with radio minihalos in their cool cores. A3444 is imaged using the
Giant Metrewave Radio Telescope (GMRT) at 333, 607 and 1300 MHz and the Very
Large Array at 1435 MHz. Most of the minihalo is contained within r<120 kpc,
but a fainter extension, stretching out to 380 kpc South-West of the center, is
detected at 607 MHz. Using Chandra, we detect four X-ray sloshing cold fronts:
three in the cool core at r=60, 120 and 230 kpc, and a fourth one at r=400 kpc
- in the region of the southwestern radio extension - suggesting that the
intracluster medium (ICM) is sloshing on a cluster-wide scale. The radio
emission is contained within the envelope defined by these fronts. We also
analyzed archival 383 MHz GMRT and Chandra observations of MS1455.0+2232, which
exhibits a known minihalo with its bright part delineated by cold fronts inside
the cool core, but with a faint extension beyond the core. Similarly to A3444,
we find a cold front at r~425 kpc, containing the radio emission. Thus the
entire diffuse radio emission seen in these clusters appears to be related to
large-scale sloshing of the ICM. The radio spectrum of the A3444 minihalo is a
power law with a steep index $\alpha=1.0\pm0.1$. The spectrum steepens with
increasing distance from the center, as expected if the minihalo originates
from re-acceleration of relativistic particles by the sloshing-induced
turbulence in the ICM.
