Crystal structure, chemical bond characteristics, and microwave dielectric properties of novel Sr2CaMoO6 ceramic at different sintering temperatures

Sintering behavior, crystal structure, and microwave dielectric properties of a novel NaY9Si6O26 ceramic

“…Notably, the refinement parameters, R WP (weighted profile R-factor) and R P (profile R-factor), for the sample sintered at 1465 • C are significantly below 15%, with R P being less than R WP . 22,23 This reinforces the conclusion that NaY 9 Si 6 O 26 ceramics indeed manifest a hexagonal structure with space group P63/m (176).…”

Effects of oxygen vacancy on bond ionicity, lattice energy, and microwave dielectric properties of CeO 2 ceramics with Yb 3+ substitution

“…where ν ij is the bond valence between atoms i and j, R ij is the bond valence parameter [35], d ij is the bond length between atoms i and j, and b = 0.37 Å. Evidently, the trends of τ f values and bond valence are similar in the single-phase region. The increase of the bond valence indicates that bond strength between the metal ions and the oxygen ions increases, giving rise to the polyhedron formed by metal ions and oxygen ions becoming structurally more stable [36], which leads to the τ f values being even closer to zero.…”

Crystal structure and microwave dielectric properties of Li2(Mg1–xCux)2Mo3O12 ceramics sintered at ultra‐low temperature

“…Notably, an abrupt and drastic increase in the standard deviation of the grain‐size distribution of the samples is observed when the value of x reaches 0.1. This suggests that the grain‐size distribution is more discrete, which can have a negative effect on the dielectric properties 41 . The non‐uniformity of grain morphology is mainly attributed to two aspects: different grain sizes caused by uneven nucleation 42 and the production of a certain amount of liquid phase during the sintering process, resulting in the driving force for grain growth dispersed in the liquid phase satisfying the following formula 43 : $$$$\begin{equation}\Delta {G}_{\mathrm{V}} = 2{\gamma }_{{\mathrm{sl}}}{V}_{\mathrm{m}}\left( {\frac{1}{{{r}^*}} - \frac{1}{r}} \right),\end{equation}$$$$where γ sl and V m are the solid–liquid interface energy and the corresponding molar volume fraction, respectively, and r * is the grain size that neither dissolves nor grows.…”

“…This suggests that the grain-size distribution is more discrete, which can have a negative effect on the dielectric properties. 41 The non-uniformity of grain morphology is mainly attributed to two aspects: different grain sizes caused by uneven nucleation 42 and the production of a certain amount of liquid phase during the sintering process, resulting in the driving force for grain growth dispersed in the liquid phase satisfying the following formula 43 :…”