Guan Zhou, Feng Chuangshi, Song Hongquan, Yang Lingxu, Wang Xin, Liu Huijun, Zhang Jiawei, Wei Fanqian, Yuan Xin, Yang Hengyong, Tang Yu, Zhang Fuxiang
Songshan Lake Materials Laboratory, Dongguan 523808, China.
College of Physics and Telecommunication Engineering, Zhoukou Normal University, Zhoukou 466001, China.
Nanomaterials (Basel). 2025 Apr 30;15(9):684. doi: 10.3390/nano15090684.
Magnéli phases exhibit significant potential for applications in electronic materials in energy conversion due to their high electrical conductivity and excellent thermal stability. In this study, single-phase TiO ( = 4, 5, 6) bulk materials were successfully prepared by a combination of the carbothermal reduction of nano-sized rutile TiO and hot-press sintering methods. The relationships between the phase evolution, microstructural features, and thermoelectric performance were investigated systematically. Synchrotron X-ray diffraction (SXRD) and scanning electron microscopy (SEM) analyses revealed that the TiO and TiO materials had single-phase structures with high densities (relative density > 97%) and no obvious grain boundary holes or microcracks. We tested the thermoelectric properties of the Magnéli phases in the temperature range of 300-1100 K. The Magnéli phases exhibited a significant temperature dependence, with peak zT values of 0.17, 0.18, and 0.14 for TiO, TiO, and TiO, respectively, at 1100 K. This variation in thermoelectric performance was mainly attributed to the synergistic effect of the oxygen vacancy concentration and the shear surface density on the carrier concentration and lattice thermal conductivity. Furthermore, the Fermi energy levels and electronic thermal conductivity of the Magnéli phases were calculated using the single parabolic band (SPB) model.
由于其高电导率和出色的热稳定性，马格内利相在能量转换电子材料中的应用具有巨大潜力。在本研究中，通过纳米尺寸金红石TiO的碳热还原和热压烧结方法相结合，成功制备了单相TiO（= 4、5、6）块状材料。系统研究了相演变、微观结构特征和热电性能之间的关系。同步辐射X射线衍射（SXRD）和扫描电子显微镜（SEM）分析表明，TiO和TiO材料具有单相结构，密度高（相对密度> 97%），且无明显晶界孔洞或微裂纹。我们测试了马格内利相在300 - 1100 K温度范围内的热电性能。马格内利相表现出显著的温度依赖性，在1100 K时，TiO、TiO和TiO的峰值zT值分别为0.17、0.18和0.14。这种热电性能的变化主要归因于氧空位浓度和剪切表面密度对载流子浓度和晶格热导率的协同作用。此外，使用单抛物线带（SPB）模型计算了马格内利相的费米能级和电子热导率。
