MAGNON SPECIFIC-HEAT IN QUASI-2-DIMENSIONAL ANTIFERROMAGNETIC MATERIALS - APPLICATION TO YBA2CU3O6 AND LA2CUO4 OXIDE SUPERCONDUCTORS

The aim of the present paper is to study the magnon specific heat by u sing the quasi-two-dimensional Heisenberg model and Zubarev's double t ime temperature dependent Green's function. We used the equation of mo tion method and the Callen decoupling method to evaluate the double ti me temperature dependent Green's functions. In antiferromagnetic mater ials, it is found that there is some axis along which the magnetic mom ent tends to align with lower energy due to the presence of anisotropi c antiferromagnetic correlation coupling. We study the role of anisotr opic antiferromagnetic coupling on the magnon specific heat. Using our theory, we have calculated the contribution of the magnon specific he at in YBa2Cu3O6 and La2CuO4 high-temperature superconducting compounds in the antiferromagnetic phase. The role of interlayer coupling betwe en CuO layers has also been studied.