The effects of tungsten (W) doping on the material properties of VO₂ films and the magnetic properties of VO₂/Ni bilayers were investigated. Doped VO₂ films are fabricated using a sol-gel synthesis technique. As seen in previous studies, the vanadium dioxide metal to insulator transition (MIT) is shifted to lower temperature and reduced in magnitude with increased W doping. While the impact on transport is quite dramatic, morphology of VO₂ is only slightly affected by W doping. We find that there is a stabilization of the rutile phase of VO₂ at room temperature and formation of a small amount of V₂WO₆ phase. VO₂/Ni bilayers show a sharp decrease in the coercivity and increase in the magnetic moment at the VO₂ structural phase transition. W doping decreases the temperature of these magnetic properties and also decreases their magnitude. The decreased magnitude of the magnetic effects, along with the stabilization of the rutile phase seen in the X-ray data, suggests that the degradation of the MIT is due to structural reasons and not solely because of added carriers to the system.

中文翻译：

---

VO 2中的W掺杂对VO 2 / Ni异质结构磁性的影响

研究了钨掺杂对VO ₂薄膜材料性能和VO ₂ / Ni双层磁性能的影响。使用溶胶-凝胶合成技术制造掺杂的VO ₂膜。如先前的研究所示，二氧化钒金属向绝缘体的转变（MIT）转移到了较低的温度，并且随着W掺杂的增加而降低了幅度。虽然对传输的影响非常显着，但W掺杂对VO _2的形貌影响很小。我们发现室温下VO ₂的金红石相稳定，并形成少量的V ₂ WO ₆相。VO ₂/ Ni双层在VO ₂结构相变时显示出矫顽力的急剧降低和磁矩的增加。W掺杂降低了这些磁性能的温度并且还降低了它们的强度。磁效应的降低以及X射线数据中金红石相的稳定化表明MIT的性能下降是由于结构原因，而不仅仅是由于系统中添加了载流子。