2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/16466We study a Heisenberg chain with nearest-neighbor (NN) J1 and next-NN J2 exchange interactions with anisotropies Delta_1 and Delta_2 respectively. We investigate by analytical and numerical methods the region of parameters for which there is a jump in the magnetization M as a function of magnetic field B. Some materials with edge sharing CuO polihedra are candidates to show an abrupt change in M(B).2 pages, 1 figure, submitted to J. Magn. Magn. Mat. Contributed paper for the International Conference on Magnetism (August 6-11, Recife, Brasil)Strongly Correlated Electronstext