Exploring the Magnetism and Magnetocaloric Effect of W‐Doped VO 2 Based on J 1 – J 2 Ising Model

• Published in: physica status solidi (b) 2023-12
• Main Authors: Liu, Li, Shi, Detai, Zhu, Wei, Bao, Qifu, Li, Siyu, Zhao, Tiangui, Liu, Kun, Li, Xiaolong, Zhou, Jianer
• Format: Article
• Language: English
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.202300316

W‐doped VO 2 exhibits a significant reduction in the metal–insulator transition temperature. In this study, the authors aim to investigate the magnetic influences of different proportions of W doping in VO 2 with a rutile structure, using the J 1 – J 2 model. The J 1 and J 2 values are calculated as 1.21 and −0.024 eV, respectively, using the generalized gradient approximation (GGA)+U method. Additionally, the J 1 – J 2 model without W doping ( x  = 0) is simulated using the Ising model, and the obtained phase transition temperature of approximately 361 K closely matches the temperature calculated by Zheng et al. based on the spin dimer model. Furthermore, employing this model, the magnetization curves and magnetic entropy change (Δ S ) are simulated for different W doping levels ( x  = 0–0.2). Through comprehensive analysis, it is found that the system exhibits the most promising research potential at a doping level of x  = 0.12. These findings deepen the understanding of the mechanisms underlying the magnetic effects of W‐doped VO 2 and provide a theoretical model guidance for future development of vanadium oxide materials.