Structural and dielectric properties of Sr5RTi3Ta7O30 (R=Sm, Y) ceramics

Characterization and dielectric properties of Sr4M2Ti4Ta6O30 (M=Pr and Eu) ceramics

“…The structure and phase transition behavior of ferroelectric phases with the compositions Ba 2 MTi 2 X 3 O 15 (M = La, Pr, Nd, Sm, Eu, Gd, Dy, Bi; X = Nb, Ta) and Ba 6 MNb 9 O 30 (M = Ga, Sc and In) were reported by West et al and Arnold et al, respectively [13,14]. Recently, some Srbased TB ceramics such as Sr 5 LnTi 3 M 7 O 30 , Sr 4 Ln 2 Ti 4 M 6 O 30 (Ln = La, Nd, Sm, Gd, Y and M = Nb and Ta) were proposed and investigated [15][16][17][18][19][20]. Extensive literature on TB compounds reveals that no work has been reported on the titled compounds.…”

Structural and dielectric properties of Ba5LnSn3Nb7O30 (Ln=La, Nd) ceramics

“…Rao et al [6] and Koshy et al [7] proposed some promising compounds with tungsten bronze (TB) structure under the formula Ba 3 (RE) 3 Ti 5 Nb 5 O 30 (RE = La, Y, Sm, Nd) for their high dielectric constants of above 130. Chen and Yang [8,10] and Fang et al [9,12] and Zhang et al [11] also reported the presence of dielectric materials with filled TB structure in the BaOLn 2 O 3 -TiO 2 -Ta 2 O 5 and SrO -Ln 2 O 3 -TiO 2 -Ta 2 O 5 (Ln = La, Sm, Nd) system with high dielectric constant above 103 and low dielectric loss in the order of 10 -3 -10 -4 . The problem for ceramics with TB structure in the above systems is the relatively large negative temperature coefficient of dielectric constant [8 -10].…”

“…It has been found that different ionic substitutions at abovementioned sites can play an important role in tailoring their physical properties [8][9][10]. In order to explore new dielectric ceramics with high dielectric constant and low temperature coefficient of dielectric constant, we decided to prepare a group of compounds with TB structure in the BaO -Ln 2 O 3 -SnO 2 -Nb 2 O 5 (Ln = La, Nd) system, and as there is no report available on the titled compounds, then we have systematically studied the structural and dielectric properties of the titled compounds Ba 5 LnSn 3 Nb 7 O 30 (Ln = La, Nd) and reported the preliminary result here.…”

High permittivity and low loss dielectric ceramics Ba5LnNiNb9O30 (Ln=La, Nd and Sm)

“…It has been found that different ionic substitutions at above-mentioned sites can play an important role in tailoring their physical properties [11,12]. Therefore, we conducted the systematic studies on the characterization and dielectric properties of Sr-based TB ceramics Sr 5 LnTi 3 Ta 7 O 30 and Sr 4 Ln 2 Ti 4 Ta 6 O 30 , Sn-contained ceramics A 5 LnSn 3 Nb 7 O 30 (A = Ba and Sr), and Zn-contained TB ceramics Ba 5 LnZnM 9 O 30 (M = Ta and Nb) [12][13][14][15][16][17][18][19][20][21]. Since very little data are available on Ni-contained TB compounds, this paper firstly presents the preparation, characterization and dielectric properties of new TB compounds Ba 5 LnNiNb 9 O 30 (Ln = La, Nd and Sm).…”