Microstructure and phase composition analysis, scanning electron microscopy (SEM) analysis for the different sintering process preparation of BST ceramics after the hot corrosion surface scanning electron microscopy (SEM) photos. By figure can see, microwave sintering and conventional sintering of the preparation of BST ceramics is only a small amount of pores, the structure is compact, grain ellipsoid or cylindric. Grew up in conventional sintered samples, abnormal particles, and the uneven distribution of grain size. Microwave sintering samples of grain size is smaller than the traditional sintering of samples, small grain size is not easy to appear empty situation, make the structure more closely, the performance of microwave sintering samples density is higher than the traditional sintering samples. For microwave sintering integrated heating, local ionization will cause acceleration and mass transfer, which makes ceramic defects such as porosity and so on are more likely to rule out inside body, structure more compact; As microwave sintering time is short, and the samples in uniform temperature distribution, restrain the grain growth, grain size distribution is relatively uniform.

Different sintering process of SEM, XRD analysis of atmospheric pressure sintering and microwave sintering of BST ceramics XRD diagrams. The figure shows that two kinds of sintering process of BST ceramics were formed the class of single-phase perovskite phase tungsten bronze BST solid solution, phase structure, the existence of the second phase is not observed, that the microwave sintering not change BST phase composition of ceramic materials. For BST tungsten bronze structure solid solution of the crystal cell parameters, this is the main according to the diffraction peak position, according to the Bragg equation, and calculated by using least-square method. By figure can see, microwave sintering reduce BST solid solution of the crystal cell parameters, unit cell volume contraction.

Different sintering process of XRD diagram of sintering process on the influence of the crystal cell parameters, the traditional sintering microwave sintering microwave dielectric performance analysis for different preparation of microwave dielectric properties of BST ceramics sintering process. Microwave sintering samples three dielectric properties than traditional sintering samples decrease slightly, the microwave dielectric properties for r = 82.89, Qf = 8450 GHz (f = 4.75 GHz), f = 22.5810-6 /. Microwave sintering makes BST interstitial cell volume decreases, and center of mobile space of ions is reduced, leading to lower permittivity sintered body. Microwave sintering BST porcelain tiny grains, grain boundary, and defects such as vacancy caused by the grain boundary has said, and thus the loss of microwave sintering BST ceramics increases, the quality factor of Qf has decreased. Resonant frequency temperature coefficient f = (+ / 2) in (1) the type of dielectric constant temperature coefficient; As thermal expansion coefficient.

F the size of the main and related. Is one of the cause of the change lattice expansion cause reduction in the number of units within the dipole, the mechanism is related to the crystal. Microwave sintering, due to the sintering time is short, small grains growth compared with conventional sintering, thermal expansion coefficient decreases, and directly led to the rise.

Different sintering process of microwave dielectric properties of microwave dielectric properties of microwave sintered atmospheric pressure sintering, and the conclusion compared with the traditional sintering, microwave sintering technology shortens the BST ceramics sintering cycle, energy conservation and efficiency, has the potential to reduce costs. Microwave sintering inhibits grain growth, crystal cell volume decreases, and makes the density of microwave sintering samples than traditional under same temperature sintered samples, and will not change the BST phase composition of ceramic material, the main crystal phase is still kind of perovskite phase Ba6 tungsten bronze - 3 xsm8 + 2 xti18o54 solid solution, the sintered body is typical of the columnar crystal. Due to internal heating, microwave sintering samples from fast sintering and microwave sintering of the small grains generally than conventional sintering samples grain and uniform. Microwave sintering of BST ceramics can obtain a better microwave dielectric properties: r = 82.89, Qf = 8450 GHz (f = 4.75 GHz), 22.5810 6 / f =.