Investigation of the temperature phase diagram of the 2D semi-classical ferrimagnetic J1−J2 model

Abstract

Abstract The temperature phase diagram (T over J 2) of the 2D semiclassical J 1 − J 2 Heisenberg model is discussed. The investigation was carried out using the self-consistent Bloch equation and a quantum statistical description of the magnetization. In addition to the three states of the zero-temperature phase diagram, the J 2 − T phase diagram shows two new phases, the paramagnetic phase and the semi-paramagnetic S 1 -Néel state. The five occurring ground states, as well as the transitions between these states, are discussed. In particular, attention is paid to the interplay between temperature and frustration.