Phase transitions and magnetization of the mixed-spin Ising-Heisenberg double sawtooth frustrated ladder

TL;DR

This paper investigates the phase transitions and magnetization properties of a mixed-spin Ising-Heisenberg double sawtooth ladder, revealing new magnetization plateaus and detailed thermodynamic behaviors at low temperatures.

Contribution

It introduces a detailed analysis of the ground-state phase diagrams and thermodynamic properties of a mixed-spin ladder with novel findings like a new magnetization plateau.

Findings

Discovery of a new magnetization plateau at M/Ms=5/6.

Magnetization and magnetic susceptibility behaviors coincide at low temperature.

Specific heat exhibits a Schottky-type peak with temperature dependence.

Abstract

The mixed spin-(1,1/2) Ising-Heisenberg double sawtooth ladder containing mixture of both spin-1 and spin-1/2 nodal atoms, and the spin-1/2 interstitial dimers is approximately solved by the transfer-matrix method. Here, we study in detail the ground-state phase diagrams, also influences of the bilinear exchange coupling on the rungs and cyclic four-spin exchange interaction in square plaquette of each block on the magnetization and magnetic susceptibility of the suggested ladder at low temperature. Such a double sawtooth ladder may be found in a Shastry-Sutherland Lattice-type. In spite of odd and even blocks spin ordering are different from each other, but due to the commutation relation between all different block Hamiltonians, phase diagrams, magnetization behavior and thermodynamic properties of the model are the same for odd and even blocks. We show that at low temperature, both exchange couplings can change the quality and quantity of the magnetization plateaus versus the magnetic field changes. Specially, we find a new magnetization plateau M/Ms = 5/6 for this model. Besides, we examine the magnetic susceptibility and specific heat of the model in detail. It is proven that behaviors of the magnetization and the magnetic susceptibility coincide at low temperature. The specific heat displays diverse temperature dependencies, which include a Schottky-type peak at a special temperature interval. We observe that with increase of the bilinear exchange coupling on the rungs, second peak temperature dependence grows.