Phase evolution and microwave dielectric properties of Li4Ti5(1+x)O12ceramics

作者：Zhang Jian; Zuo Ruzhong^*; Wang Yang; Qi Shishun

来源：Materials Letters, 2016, 164: 353-355.

DOI：10.1016/j.matlet.2015.10.160

• Ceramics
• Cubic spinel structure
• Low sintering temperature
• Microwave dielectric properties
• Microwave property
• Phase evolutions
• Sintering behaviors
• Solid state method

Li4Ti5(1+x)O12(-0.15≤x≤0.10) ceramics were successfully prepared via a conventional solid state method. The phase evolution, sintering behavior and microwave dielectric properties were systematically studied. As x≥0, TiO2appeared as a secondary phase. Single phase Li4Ti5O12was obtained at x=-0.10 to -0.05 with a cubic spinel structure, belonging to Fd-3m space group. Another impurity Li2TiO3arose at x=-0.15, probably resulting from the overmuch Ti vacancies in the structure. Highest Εr(∼26) and Q×f (∼68000 GHz) were achieved in pure-phase Li4Ti5O12(x=-0.10), because suitable excess lithium not only compensated for the volatilization of lithium but greatly promoted the sintering behavior. Moreover, with the help of TiO2, τfvalues of the ceramics within 0≤x≤0.10 were adjusted to near zero, accompanied with excellent microwave dielectric properties of Εr=18∼24, Q×f∼10000 GHz. Furthermore, these samples were chemically compatible with Ag. Thus, the Li4Ti5(1+x)O12(-0.15≤x≤0.10) ceramics could be promising medium permittivity materials in consideration of their low cost, low sintering temperature and superior properties.

• 单位
  合肥工业大学