Upper limit of x in Ba6−3xNd8+2xTi18O54 new tungsten bronze solid solution

Microstructure and Microwave Dielectric Properties of Ba3.75Nd9.5Ti18−z (Mg1/3Nb2/3) z O54 Ceramics

“…[1][2][3][4][5][6] The design of new microwave dielectric materials is guided by three criteria updated by Freer and Azough. 2 Materials should have a high relative permittivity to minimize the size of the resonant components, as high as possible Qf, and a near zero temperature coefficient of resonant frequency (s f ).…”

“…However, high positive s f (+60 ppm/°C to +150 ppm/°C) has always prohibited their wide utilization. 1,[3][4][5][6][8][9][10] Unfortunately, the effect of tetravalent ions substitution at the b-site has been reported to adjust s f , and a low dielectric constant and a high dielectric loss, which demand further optimization, were obtained. [11][12][13] However, this indicated that b-site substitution would be a possible way to modify the s f value.…”

“…Ba 6À3x Nd 8+2x Ti 18 O 54 (x = 0.75) exhibits relative low s f (+60 ppm/°C), therefore minor (Mg 1/3 Nb 2/3 ) 4+ substitution content would effectively drive s f to zero. 1,3,8,9 In the present work, Ba Chemical Reagent), with purity ‡99.5%. The mixtures were ball-milled in nylon jars with zirconia balls and distilled water for 12 h. After drying, the powder was calcined at 1000-1100°C for 5 h. Then, the calcined powders were produced with 5 wt.% PVA added in the size of 15 mm in diameter and 6 mm in thickness under a pressure of 220 kg/cm 2 .…”

Phase Relations inBa6−3xLn8+2xTiSnashall1, Liu2, Brink3 et al. 2013Advances in Condensed Matter Physics1010View full textAdd to dashboardCite

“…This investigation, particularly, focuses on changes in morphology and the effects of prolonged annealing, which had previously been shown to result in unexplained cell parameter and dielectric properties variation deserving of further attention [10]. [8,[11][12][13]; therefore the compositions investigated in this paper were = 0.33, 0.5, 0.67, henceforth referred to as compositions A, B, and C, respectively. To observe the effects of varying the size of the lanthanide, for each composition A, B, and C, samples for = 0, 0.2, 0.4, 0.6, 0.8, and 1 were synthesised, henceforth referred to as A0, A2, A4, and so forth.…”