  The conditions for the formation of zero-energy peak in the density of states
(DOS) in the normal metal / insulator / diffusive ferromagnet / insulator /
s-wave superconductor (N/I/DF/I/S) junctions are studied by solving the Usadel
equations. The DOS of the DF is calculated in various regimes for different
magnitudes of the resistance, Thouless energy and the exchange field of the DF,
as well as for various resistances of the insulating barriers. The conditions
for the DOS peak are formulated for the cases of weak proximity effect (large
resistance of the DF/S interface) and strong proximity effect (small resistance
of the DF/S interface).
