Microwave dielectric properties of Ba5+nTinNb4O15+3n ceramics

Microstructure and microwave dielectric properties of Ba5Nb4O15–BaWO4 composite ceramics

“…Recently, some hexagonal perovskite-like oxides have been investigated and they have been found to be the candidate materials for dielectric resonators in base station of telecommunication systems [2][3][4][5][6][7][8][9][10]. The structure and microwave dielectric properties of A 5 B 4 O 15 (A = Ba, Sr, Mg, Ca, Zn; B = Nb, Ta) type ceramics have been investigated [11,12].…”

Effects of Sr substitution on microwave dielectric properties of Ba3LaNb3O12 ceramics

“…To meet the requirements for use in such wide applications, the microwave materials should possess appropriate properties like (a) high dielectric constant (ε r ) for miniaturization, (b) high unloaded quality factor (Q u ) or low dielectric loss for better selectivity and (c) low temperature coefficient of resonant frequency ( f ) for frequency stability. Although several compounds such as Ba(Zn 1/3 Ta 2/3 )O 3 , BaTi 4 O 9 , Ba 2 Ti 9 O 20 , (Zr,Sn)TiO 4 , and Ba 6−3x Re 8+2x Ti 18 O 54 (Re = Nd, Sm, La) systems have been reported for practical applications [2], active research is still going on for new compounds due to the great demand for a variety of materials with varying dielectric constants [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18].…”

“…These compounds are characterized by high ε r up to 56 and high quality factors with Q u × f value up to 88,000 GHz. We also investigated the microwave dielectric properties of three end members of A n B n−1 O 3n (n = 6-8) perovskites, such as Ba 6 [11] and found that values of ε r and f of these ceramics gradually increase while the Q u × f value decreases as the number of n increases. Therefore, the A n B n−1 O 3n -type ceramics with n < 5 might have superior properties.…”

Microwave dielectric properties and Far-infrared spectroscopic analysis of Ba5+nTinNb4O15+3n (0.3<n<1.2) ceramics

“…8 Furthermore, Fang et al reported the microwave dielectric properties of cation-deficient hexagonal perovskites Ba 5+n Ti n Nb 4 O 15+3n (n = 1, 2, 3) system. 9 The crystal structure of cation-deficient hexagonal perovskite type materials Ba 5+n Ti n Nb 4 O 15+3n have been studied by some authors through the Rietveld refinement method and TEM analysis. According to Duivenboden et al Ba 6 TiNb 4 O 18 (n = 1) consists of a framework of close-packed BaO 3 layers, 18R (hhcccc) 3 .…”