Magnetic properties of delta- and kagome-like chains with competing interactions

Abstract

We study the delta-chain with spin-$1$ on basal sites and
spin-$\frac{1}{2}$ on apical sites. The Heisenberg interaction
between neighbor basal spins is antiferromagnetic (AF) and the
interaction between basal and apical spins is ferromagnetic (F).
We show that the magnetization curve of this model is the same as
that of the spin-$\frac{1}{2}$ kagome-like chain with competing
Heisenberg interactions. The ground state phase diagram of the
latter as a function of the ratio between the AF and F
interaction, $\alpha $, consists of the ferromagnetic,
ferrimagnetic and singlet phases. We study the magnetic properties
in each ground state phase and analyze the magnetization curves.
We show that there are magnetization plateaus and jumps in
definite regions of value $\alpha$. We compare the magnetic
properties of considered models with those of the
spin-$\frac{1}{2}$ delta chain.