Investigation of the effect of particle size on the 10 GHz microwave properties of Ba_1−xSr_xTiO₃ / MgO composite ceramics

Abstract

The objective of this study is to determine the effect of milling on the X-Band microwave properties of Ba,, ,TiO, / MgO {wt% MgO= 0 to 60 wt%} composites. At low frequency, the effect of the reduction of the overall particle size of the materials from attritor milling is dependent on the additive oxide content; for samples with oxide content > 5.0 wt%, the dielectric constant, and tunability (%) are decreased. Whereas, milled Ba,,Sr,,TiO, / MgO"' (wt% MgO= 0 to 1 wt%} composites exhibit low loss tangents, higher tunabilities, and higher dielectric constants than unmilled samples. The present study is focused on the effect of milling on the diekectric properties of Ba, ,Sr,,TiO, / MgO composites at microwave frequency. The samples were evaluated in a 10 GHz resonator cavity. Additionally, the effect of barium content and MgO content on the 10 GHz dielectric properties of Ba$r,.,TiO, (x = 0.45, 0.50, 0.55, 0.60) / MgO (MgO = 1 -60 Wt%) are investigated. These results are correlated with relevant material characterization techniques including FT-Raman studies. 342/[862]J. SYNOWCZYNSKI r t ul.

BST ceramics: Effect of attrition milling on dielectric properties

“…Sengupta et al showed the feasibility of such materials by making composites of BST and various nonferroelectric oxides. 13,14 More recently, the authors studied the effect of milling composite powders on the optical 15 and microwave 16 properties of ceramics, but they give not much information on the correlation between microstructure and dielectric properties.…”

Preparation and microstrutures of BSTO/MgO ferroelectric materials for phase shift

“…Numerous studies have been carried out on barium strontium titanate (BSTO) ferroelectric materials. However, there are few reports on microwave dielectric properties of BSTO because it is diffi cult to fi nd a technique which can accurately measure the dielectric properties of the materials with a high dielectric constant and a low dielectric loss [2] . Moreover, most work has always focused on the singlephase BSTO system, whereas, BSTO-based composite systems such as BSTO/MgO, BSTO/polymer etc seem to be ignored.…”

Electrically tunable dielectric materials and strategies to improve their performances

“…For example, it has been reported that the dielectric losses of Ba 0.5 Sr 0.5 TiO 3 ceramic, thick films and thin films can be lowered to a level that is acceptable for device applications though the addition of MgO, Al 2 O 3 and ZrO 2 [91,92]. Among the three oxides, MgO was the best dopant in terms of reducing dielectric losses, which, therefore, led to extensive studies on the doping effect of MgO on the dielectric tunable properties of Ba 1-x Sr x TiO 3 [93][94][95][96][97][98][99][100][101][102][103][104][105]. Joshi and Cole [102][103] prepared MgO-doped Ba 0.5 Sr 0.5 TiO 3 (BST) thin films using metalorganic solution deposition technique.…”