Magnetic Properties Of Ferromagnetic Longrange Interacting Spin Chain With The Antiferromagnetic Nearest-neighbor Interaction

With the rapid development of scientific research and the emergence of new experimental means,physics has been greatly developed.Correspondingly,the study of solid magnetism has entered a deeper level,and researchers' interest in the study of physical properties of materials is also unprecedentedly high.At present,there have been a large number of ferromagnetic properties,ferromagnetic properties,ferromagnetic properties of the theory of research results,people used a lot of different theoretical methods in the process of research,such research undoubtedly provides a great help for the application and development of materials in the near quantum field.In this paper,the phase diagram and low temperature properties of the long range Heisenberg ferromagnetic spin chain with antiferromagnetic nearest-neighbor action are studied by using the Onsager reaction field theory and the modified spin wave theory.We first obtain the static susceptibility of the Heisenberg chain with long range ferromagnetic interaction and antiferromagnetic nearest-neighbor interaction and the self-consistent equation of the reaction field coefficient by using the Onsager reaction field theory.The zero-temperature phase diagram of one-dimensional Heisenberg ferromagnetic link is obtained by calculating its critical temperature.The combined effects of long range interaction and antiferromagnetic nearest-neighbor interaction on critical temperature and static susceptibility are also discussed.Based on the idea of total magnetization is zero takahashi,we designed at the same time there are ferromagnetic long-range interactions and antiferromagnetic nearest neighbor interaction under the influence of the modified scheme of spin wave theory,by introducing Lagrange multiplier Hamiltonian to eliminate the heat dissipation,usually to keep the magnetization is zero,aims to research on modified spin wave theory framework,The influence of long range ferromagnetic interaction and antiferromagnetic nearest-neighbor interaction on the thermodynamic properties of the system at low temperatures.The rest of this article consists of four parts.The first part elaborates the research background and practical significance,and then introduces the research content and research methods used in this paper.In the second part,the Onsager reaction field theory is applied to the one-dimensional Heisenberg model,which includes the long range ferromagnetic interaction and the antiferromagnetic nearest-neighbor interaction.In the third part,we design a scheme based on Takahashi's idea that the usual thermal divergence is eliminated by introducing Lagrange multipliers into the Hamiltonian,thus keeping the magnetization to zero.Finally,we summarize our conclusions in the fourth part.