Uncompensation Effect in a One-Dimensional Alternating-Spin Ising Ferrimagnet with Competing Interactions

Abstract

The characteristic short-range orders (SROs) in a one-dimensional Ising ferrimagnet, which is composed of alternating spins withdifferent spin quantum numbers, Lande g-factors, and next-nearest-neighbor interactions, are investigated by the numerically exact calculation ofa nonsymmetric transfer matrix.Due to the uncompensating moments, some SROs in the system show very different characteristics from those in the uniform-spin ANNNI chain; (i) the peculiar two-peaked structure of the static spin structure factor {\cal S}(q), indicatingnot two different SROs but the same SRO, and (ii) an unusual thermal recovery of the ferrimagnetic SRO, carrying three disorder points, under a non-zero external field.Decaying features of the characteristic SROs and the magnetic behavior of the system with variation of external field are alsodiscussed.