Pressure Dependence of Exchange Parameters and Neel Temperature in La₂CuO₄

Abstract

Microscopic mechanisms responsible for the observed pressure dependencies of the Neel temperature TN and parameters of isotropic and anisotropic exchange interaction in the orthorhombic antiferromagnet La2CuO4 are investigated. Within the framework of the Anderson microscopic theory of superexchange interaction, the expressions establishing interrelation between parameters of isotropic and anisotropic (both symmetric and antisymmetric) exchange interactions and by the structural parameters describing the Cu‐O‐Cu bonding angle and the Cu‐O bond length in La2CuO4 are obtained. Experimentally determined pressure dependencies of structural parameters by H. Takahashi et al., allow one to present pressure dependencies of exchange parameters and TN in an apparent form.

Effects of Frustration and Dzyaloshinskii–Moriya Interaction on the Spin‐1/2 Anisotropic Heisenberg Antiferromagnet with the Application to La2CuO4

“…[5,6,8] Our earlier results [19][20][21][22] also suggest that the model with the NNN interaction gives predictions in better agreement with the experimental data. Besides the aforementioned, the choice of the dominant interactions is supported by the fact that these interactions, especially NN, NNN, and DM interaction, but also spin anisotropy to a lesser extent, show a distinctive pressure dependence, [23,24] enabling one to affect the phase transition temperature by applying high pressures on the system. Having this in mind, the purpose of this article will be to study the 2D antiferromagnetic Heisenberg model with the uniaxial XXZ spin anisotropy, DM interaction, and in-plane frustration included.…”

Effects of frustration and Dzyaloshinskii-Moriya interaction on the spin-1/2 anisotropic Heisenberg antiferromagnet with the application to La2CuO4

“…Our earlier results [19][20][21][22] also suggest that the model with the NNN interaction gives predictions in better agreement with the experimental data. Beside the aforementioned, the choice of the dominant interactions is supported by the fact that these interactions, especially NN, NNN and DM interaction, but also spin anisotropy to a lesser extent, show a distinctive pressure dependence [23,24], enabling one to affect the phase transition temperature by applying high pressures on the system. Having this in mind, the purpose of this paper will be to study 2D antiferromagnetic Heisenberg model with the uniaxial XXZ spin anisotropy, DM interaction and in-plane frustration included.…”