Novel sintering and band gap engineering of ZnTiO3 ceramics with excellent microwave dielectric properties

2017 ◽  
Vol 5 (16) ◽  
pp. 4040-4047 ◽  
Author(s):  
Shenhui Lei ◽  
Huiqing Fan ◽  
Xiaohu Ren ◽  
Jiawen Fang ◽  
Longtao Ma ◽  
...  

Pure phase ZnTiO3 ceramics were successfully synthesized for the first time by a solid state reaction method.

2011 ◽  
Vol 687 ◽  
pp. 199-203 ◽  
Author(s):  
Ching Fang Tseng

The microwave dielectric properties of the Mg(Zr0.05Ti0.95)O3ceramics with CuO addition were investigated. All specimens were prepared by solid-state reaction method and sintered at 1270-1420°C for 4 h. When CuO was added, the second phases of MgTi2O5, TiO2and liquid phase were produced. For specimens with 1.5 wt% CuO sintered at 1300°C, the dielectric constant,Q´fand tfvalues are 18.2, 223000 GHz and -2 ppm/°C, respectively.


2012 ◽  
Vol 512-515 ◽  
pp. 1198-1202
Author(s):  
Jia Mao Li ◽  
Tai Qiu

Microstructures and microwave dielectric properties of Ca(Sm0.5Nb0.5)O3 ceramics, prepared by a conventional solid-state reaction method, were systematically investigated by varying calcining temperature, sintering temperature and cooling rate. The XRD result showed that a single Ca(Sm0.5Nb0.5)O3 phase could be synthesized at a calcining temperature of 1200 °C. Optimized combination of microwave dielectric properties of εr = 22.36, Q×f = 18030 GHz and τf = -31.2 ppm/°C was obtained for furnace-cooled Ca(Sm0.5Nb0.5)O3 ceramics sintered at 1550 °C for 4 h. However, some microcracks were found from the microstructures of the furnace-cooled specimens. Further, the Q×f value could be increased by controlling the cooling rate during the sintering process due to the disappearance of microcracks in the final material. With a cooling rate of 2 °C/min, Ca(Sm0.5Nb0.5)O3ceramics exhibited an enhanced Q×f value of 37130 GHz.


2007 ◽  
Vol 280-283 ◽  
pp. 35-38 ◽  
Author(s):  
Ai Min Yang ◽  
Wei Chen ◽  
Lan Luo

(1-x)La2/3TiO3-xLa(Mg1/2Ti1/2)O3 ceramics with x ranging from 0.01 to 0.3 were prepared by the conventional solid-state reaction method. Microstructure and microwave dielectric properties were studied. The perovskite compound La2/3TiO3 is stabilized when x = 0.1. The content of La2/3TiO3 increases with increasing x from 0.01 to 0.1, and thereafter decreases when x > 0.1. The same tendency was also observed on measuring the dielectric constant, temperature coefficient of resonant frequency and Q× ƒ. A maximum permittivity of 77.35 was achieved with these stabilized La2/3TiO3 ceramics. Close to zero τf value (1 ppm/°C) was obtained at x=0.3, but its Q× ƒ value was relative low.


2007 ◽  
Vol 336-338 ◽  
pp. 287-289
Author(s):  
Wei Wang ◽  
Zi Long Tang ◽  
Zhong Tai Zhang

(1-x)(Ca0.61Nd0.26)TiO3-x(Li0.5Sm0.5)TiO3 (0.2 ≤ x ≤ 0.7) ceramics were prepared by solid-state reaction method and the microwave dielectric properties of the resultant materials at different (Li0.5Sm0.5)TiO3 contents were investigated. A single phase of perovskite in all samples was confirmed by XRD patterns. With increasing (Li0.5Sm0.5)TiO3 content, Q×f value and dielectric constant (εr) decrease slightly and the temperature coefficients of the resonant frequency (τf) of the specimens decreases noticeably. The optimum parameters, i.e.,εr = 109, Q×f = 5259 GHz and τf = ~0 ppm/°C, for the composition of 0.4(Ca0.61Nd0.26)TiO3-0.6(Li0.5Sm0.5)TiO3 was obtained when keep the calcination temperature at 1250°C for 3 h.


2011 ◽  
Vol 01 (04) ◽  
pp. 379-382 ◽  
Author(s):  
DI ZHOU ◽  
LI-XIA PANG ◽  
JING GUO ◽  
YING WU ◽  
GAO-QUN ZHANG ◽  
...  

In the present work, a novel low temperature firing Bi 3 FeMo 2 O 12 ceramic was synthesized via the solid-state reaction method. The monoclinic Bi 3 FeMo 2 O 12 phase can be formed at a low temperature 670°C. A relative density above 96% can be obtained when sintering temperature is above 800°C. The Bi 3 FeMo 2 O 12 ceramic sintered at 845°C for 2 h shows high microwave dielectric performance with a permittivity ~27.2, a Qf value of 14,500 GHz and a temperature coefficient of -80 ppm/°C. It might be a candidate for low temperature co-fired ceramics technology.


2019 ◽  
Vol 37 (4) ◽  
pp. 639-644 ◽  
Author(s):  
Abdul Manan ◽  
Asif Nawaz ◽  
Arbab Safeer Ahmad ◽  
Atta Ullah ◽  
Arshad Hussain Wazir ◽  
...  

AbstractMg0.95Ni0.05Ti0.98Zr0.02O3 and CaTiO3 were prepared separately using solid state reaction method. The effect of CaTiO3 addition on the microwave dielectric properties of Mg0.95Ni0.05Ti0.98Zr0.02O3 was investigated to get low loss and temperature stable ceramics in (1 – x)Mg0.95Ni0.05Ti0.98Zr0.02O3-xCaTiO3 series. Mg0.95Ni0.05Ti0.98Zr0.02O3 formed as the major phase along with Mg0.95Ni0.05Ti2O5 phase that formed as minor secondary phase for the composition with x = 0. Microwave dielectric properties ∈r ~ 17.1, Qufo of 195,855 GHz and τf of –46.3 ppm/°C were obtained for the composition with x = 0. The positive τf value of CaTiO3, tuned the τf value of Mg0.95Ni0.05Ti0.98Zr0.02O3 through zero and ∈r ~ 28.4, Qufo ~ 108,775 GHz and τf ~ 3.1 ppm/°C were attained for x = 0.15 in this study. This composition is the best choice for high frequency applications.


2012 ◽  
Vol 472-475 ◽  
pp. 2107-2110 ◽  
Author(s):  
Jin Liang Huang ◽  
Yong Jun Gu ◽  
Li Hua Li ◽  
Qian Li ◽  
Zhong Yan ◽  
...  

The BCB (BaCu(B2O5)) powders were synthesized by solid state reaction method and its effects on the microstructures, the phase formation and the microwave dielectric properties of MCT (Mg0.95Ca0.05TiO3) ceramics were investigated. BaO and B2O3 first forms BaB2O4, and then BaB2O4 reacts with CuO forming BCB. The sintering temperature of MCT ceramics with as-synthesized BCB addition can be effectively lowered from 1450°C to 1100°C due to the liquid phase effect. The formation of second phase (MgTi2O5) was restrained. The 3wt% BCB-doped MCT ceramics sintered at 1100°C for 3h have optimum microwave dielectric properties of Kr=21.5, Q×f=28000GHz, and TCF=-3.3ppm/°C. Obviously, BCB could be a suitable sintering aid that improves densification and microwave dielectric properties of the MCT ceramics.


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