Preparation of novel titanium-niobium-oxygen composite ceramic with excellent thermoelectric properties using the high-pressure and high-temperature method. Issue 12 (September 2022)

• Record Type: Journal Article
• Authors: Zhou, Dayi; Gao, Shan; Chen, Yaqi; Chen, Qi; Fan, Xin; Wang, Yao; Chang, Lijie; Wang, Jian; Ma, Hongan; Zhang, Yuewen
• Is Part Of: Journal of the European Ceramic Society. Volume 42:Issue 12(2022)
• Page Start: 4980
• Page End: 4986
• Publication Date: 2022-09
• Subjects: High pressure and high temperature -- Titanium oxide -- Thermoelectricity -- Microstructure -- SEM; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2022.05.016
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: Titanium oxide is a promising thermoelectric material because of its high stability and low cost. We synthesize novel titanium-niobium-oxygen composite ceramics directly from elementary substance Nb and TiO2 under high-pressure and high-temperature (HPHT) in this work. Elemental substance Nb will reduce TiO2 to Magnèli phase titanium oxide at high pressure and high temperature. In this process, elemental substance Nb is oxidized to various niobium oxides. The experimental results show that the composite ceramics have a special 'pore' microstructure, and their thermoelectric and mechanical properties are very prominent among metal oxide thermoelectric materials. After repeated tests, the optimum concentration sample zT value is 0.313 at 973 k, with a Vickers hardness of 7.06. This work provides a novel concept for improving the performance of TiO2 by reducing it with metal elementary substances other than Ti.