  We present a Monte Carlo study of the magnetic properties of thin cylindrical
nanowires composed of a ferromagnetic core and an antiferromagnetic shell
implementing a classical spin Hamiltonian. We address systematically the impact
of interface exchange coupling on the loop characteristics and the
magnetization reversal mechanism. We study the effect of shell
polycrystallinity on the characteristic fields of the isothermal hysteresis
loop (coercivity, exchange-bias). We demonstrate that coupling to a
polycrystalline antiferromagnetic shell increases the critical core diameter
for transition from transverse to vortex domain walls.
