Exploring the Magnetism and Magnetocaloric Effect of W‐doped VO₂ based on J₁‐J₂ Ising model

W‐doped VO₂ exhibits a significant reduction in the metal‐insulator transition temperature. In this study, we aim to investigate the magnetic influences of different proportions of W doping in VO₂ with a rutile structure, using the J₁‐J₂ model. The J₁ and J₂ values are calculated as 1.21 eV and ‐0.024 eV, respectively, using the GGA+U method. Additionally, we simulate the J₁‐J₂ model without W doping (x = 0) using the Ising model, and the obtained phase transition temperature of approximately 361 K closely matches the temperature calculated by Huihuo Zheng et al. based on the spin dimer model. Furthermore, employing this model, we simulate the magnetization curves and magnetic entropy change (ΔS) for different W doping levels (x = 0 ∽ 0.2). Through comprehensive analysis, we find that the system exhibits the most promising research potential at a doping level of × = 0.12. These findings deepen our understanding of the mechanisms underlying the magnetic effects of W‐doped VO₂ and provide a theoretical model guidance for future development of vanadium oxide materials.

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