Ordering and quality factor in 0.95BaZn1/3Ta2/3O3–0.05SrGa1/2Ta1/2O3 production resonators

Abnormal variation of microwave dielectric properties in A/B site co-substituted (Ca1−0.3xLa0.2x)[(Mg1/3Ta2/3)1−xTix]O3 complex perovskite ceramics

“…11 Davies and Tong 12 attributed the high Q values to the stabilization of the ordering-induced domain boundaries by the partial segregation of zirconium. Meanwhile, the same abnormal high Q states were obtained in the middle compositions of both Ba[Mg 1/3 (Nb x/4 Ta (4−x)/4 ) 2/3 ]O 3 13 and Ba[(Mg 1−x Zn x ) 1/3 Nb 2/3 ]O 3 14 systems, in which the substituted ions Nb 5+ and Zn 2+ have almost the same radiuses as the Ta 5+ and Mg 2+ ions and should enter the same sites as the Ta 5+ and Mg 2+ ions located on in the perovskite structure, respectively.…”

“…1,2 It is well recognized that the 1:2 B-site cation ordering is critical for optimizing the dielectric properties, especially the quality factor Q for those ceramics. [3][4][5] Enhanced cation ordering has been widely sought after to achieve high-Q states by extended high temperature annealing. 6,7 However, some abnormal high-Q states were obtained in many Ba(B 1/3 B 2/3 )O 3 ceramics by introducing small amounts of dopants into the B sites instead of long time annealing.…”

Order–disorder behaviour in 0.9Ba([Zn0.60Co0.40]1/3Nb2/3)O3–0.1Ba(Ga0.5Ta0.5)O3 microwave dielectric resonators

“…13,14 The presence of 1:2 ordered regions distributed throughout grains indicates that Co readily substitutes for Zn in the ordered trigonal supercell, defining the valence state as Co 2+ . In addition, it is clear that the addition of 10% BGT to BCZN is insufficient to suppress completely 1:2 ordering.…”

“…The commensurate increase of MW Q with the degree of order observed in BCZN-BGT is consistent with observations on BZT-based compositions. [3][4][5]9,13,14 …”

“…This was accompanied by a decrease in the sintering time at temperature to achieve optimum Q. In light of more recent studies, 13,14 it seems likely that the 1:2 long-range ordered phase transition temperature in BZT-BZ was suppressed to below 1510 • C as BZ concentration increased since the electron diffraction data obtained as a function of composition were similar to those obtained as a function of temperature by Reaney et al in pure BZT 13 and BZT-SGT 14 .…”