CaNb2O6 ceramics prepared by a reaction-sintering process

Synthesis of temperature-stable microwave dielectric ceramics NiNb2O6 with TiO2 addition

“…This might have been the reason for the remarkable decrease in the content of the NiO phase observed in the pellets sintered at 1270 • C. In previous studies, a corundum-like Mg 4 Nb 2 O 9 phase was often formed during the synthesis of a columbite MgNb 2 O 6 phase [11,12]. In our study of the NiNb 2 O 6 ceramics prepared via the reaction-sintering process, single phase NiNb 2 O 6 ceramics could be obtained [9]. Therefore, the addition of 8 mol% TiO 2 resulted in the formation of the NTN-like and N4N2 phases.…”

“…Microwave dielectric properties ε r = 20.7, Qxf = 19800 GHz, and f = −31.9 ppm/ • C were obtained for NiNb 2 O 6 ceramics sintered at 1300 • C for 2 h. ε r ∼ 45, Qxf = 5400-7700 GHz, and f ∼ 73 ppm/ • C were obtained for 0.7NiNb 2 O 6 -0.3TiO 2 ceramics. ε r ∼ 50, Qxf = 3800-5700 GHz, and f ∼ 99 ppm/ • C were obtained for 0.6NiNb 2 O 6 -0.4TiO 2 ceramics [9]. f decreased as the TiO 2 content decreased in the NiNb 2 O 6 -TiO 2 ceramics.…”

“…A pure columbite CaNb 2 O 6 phase was successfully obtained. After sintering at 1420 • C for 2 h, a density of 4.37 g/cm 3 (92% of the theoretical value) was obtained [8]. Microwave dielectric properties ε r = 20.7, Qxf = 19800 GHz, and f = −31.9 ppm/ • C were obtained for NiNb 2 O 6 ceramics sintered at 1300 • C for 2 h. ε r ∼ 45, Qxf = 5400-7700 GHz, and f ∼ 73 ppm/ • C were obtained for 0.7NiNb 2 O 6 -0.3TiO 2 ceramics.…”

Phase Evolution, Microstructure, and Microwave Dielectric Properties of Reaction-Sintered Li2ZnTi3O8 Ceramic Obtained Using Nanosized TiO2 Reagent

“…15 Many ceramic materials such as Ba 2 Ti 9 O 20 , CaNb 2 O 6 , Ba 5 Nb 4 O 15 , and Li 2 MgTi 3 O 8 have also been prepared by the reaction-sintering process. [16][17][18][19] In this work, LZT ceramics were synthesized using nanosized TiO 2 reagent to study the effect of this reagent and the reaction-sintering process on the densification, phase distribution, microstructure, and dielectric properties. We attempted to promote the Q Â f value and also to enhance the s f value of the LZT ceramic through the formation of TiO 2 secondary phase at high sintering temperature.…”

Non-calcining process for CuAlO2 and CuAl0.9Ca0.1O2 ceramics

“…Other Pb-based complex perovskite ceramics were also produced by this reaction-sintering process successfully. In recent studies, some microwave dielectric ceramics such as BaTi 4 and NiNb 2 O 6 were also prepared successfully via this reactionsintering process [20][21][22][23][24]. In this study, synthesis of CuAlO 2 and CuAl 0.9 Ca 0.1 O 2 ceramics using a reaction-sintering process were investigated.…”