  The magnetic excitation spectrums of charge stripe ordered La(2-x)Sr(x)NiO(4)
x = 0.45 and x = 0.4 were studied by inelastic neutron scattering. We found the
magnetic excitation spectrum of x = 0.45 from the ordered Ni^2+ S = 1 spins to
match that of checkerboard charge ordered La(1.5)Sr(0.5)NiO(4). The distinctive
asymmetry in the magnetic excitations above 40 meV was observed for both doping
levels, but an additional ferromagnetic mode was observed in x = 0.45 and not
in the x = 0.4. We discuss the origin of crossover in the excitation spectrum
between x = 0.45 and x = 0.4 with respect to discommensurations in the charge
stripe structure.
