Determination of 1:2 Ordered Domain Boundaries in Ba[(Co, Zn_, Mg)_1/3Nb_2/3]O₃ Dielectric Ceramics

Abstract

The boundaries of 1:2 ordered domains in Ba[(Co, Zn, Mg)1/3Nb2/3]O3 perovskite ceramics are comprehensively studied by high‐resolution transmission electron microscopy (HRTEM) on the base of atomic position simulation. The atomic configurations for four types of twin boundaries are determined. A‐type and B‐type boundary, which lie along (001)c and (110)c planes, respectively, are conservative. C‐type boundary parallels to (111)c plane, while Г‐type boundary is perpendicular to (111)c plane. At C‐type and Г‐type boundary, atomic intersection leads to a buffer layer, among which the B‐site cations are generally disordered. The width of Г‐type boundary is larger than that of C‐type boundary, so is the perturbation to the system. The energy of four types of twin boundaries is proved to be “A‐type & B‐type < C‐type < Г‐type” according to the magnitude of the destabilization to the system. Single antiphase boundary (APB) is considered to be nonconservative. However, when combined with conservative twin boundary, an extra ordered structure with a periodicity of 1.24 nm along [001]c direction and a periodicity of 0.87 nm along [110]c direction forms. The boundary regions are indeed stabilized by the new superlattice.

Ordering effect on the electrical properties of stoichiometric Ba3CaNb2O9-based perovskite ceramics

“…2 (c) displays the dependence of the perceptual area of 1:1 and 1:2 peaks on the order state. In this sense, the 1:2 ceramic should contain large 1:2 or-dered domains and 1:1 domain boundary, as recently demonstrated by Ma et al for the Ba 3 (Co, Zn, Mg)Nb 2 O 9 perovskites [51]. On the contrary, the existence of large 1:1 ordered domain should better describe the Raman spectrum of 1:1 ceramic, with some regions containing short range 1:2 order, since we have detected a mode at ~ 827 cm -1 .…”

Raman signatures of monoclinic distortion in (Ba1−xSrx)3CaNb2O9 complex perovskites

“…Recently, Ma et al . analyzed the boundary regions of 1:2 ordered domain in Ba 3 (Co, Zn, Mg)Nb 2 O 9 perovskites by using high‐resolution transmission electron microscopy technique, detecting an extra stabilized ordered structure in these regions . In practice, it means that there are two well‐defined zones in the crystallites containing 1:1 (domain boundary) and 1:2 (domain) orders at B site.…”

Ba‐based complex perovskite ceramics with superior energy storage characteristics

“…The obvious domain boundaries can be observed from both bright‐field and dark‐field images from Figure 5C,D) For the samples whose annealing time extends to 36 hours, the ordering domains have enough time to grow, coarsening to be larger than 200 nm even inside the grain, and then impinge at the boundaries (see the dark‐field image from Figure 5F). It has been studied that these domain boundaries contain different degrees of local atomic disturbance, intersecting the anion layers adjacent to the interface or even disrupting all the anion layers in the surrounding domains when the energy of domain boundary is high, and the domain boundaries with high energy barrier tend to occur between the ordering domains with large size (>200 nm) 32,47 . These domain boundaries for large domains contribute to blocking charge migration under an electrical field as the high energy barrier needs to be overcome, thus the electrical resistivity gets increased.…”