Hydrothermal synthesized AgNbO3 powders: Leading to greatly improved electric breakdown strength in ceramics

Silver niobate perovskites: structure, properties and multifunctional applications

“…It was reported that pure AgNbO 3 powders can be synthesized via hydrothermal processing at 160-240 C using analytical grade NH 4 HF 2 , Nb 2 O 5 , and Ag 2 O as raw materials in an acid solution (pH ¼ 3). 29,30 Other chemical methods, such as sol-gel and coprecipitation have also been developed, using Ag and Nb alkoxides or citrates as precursors, with a ring step performed at 650 or 800 C that burns off the organic ligands and leads to the formation of AgNbO 3 . 31 The color of the AgNbO 3 synthesized powders is usually milk-like or faint yellow, but it becomes darker, from red to gray, under visible-light.…”

“…It was reported that pure AgNbO 3 powders can be synthesized via hydrothermal processing at 160–240 °C using analytical grade NH 4 HF 2 , Nb 2 O 5 , and Ag 2 O as raw materials in an acid solution (pH = 3). 29,30…”

Synergic Enhancement of Energy Storage Density and Efficiency in MnO2-Doped AgNbO3@SiO2 Ceramics via A/B-Site Substitutions

“…In particular, AFE ceramics normally display near-zero P r at a low electric field and great polarization changes during AFE-FE phase transitions, which contributes to a large W rec . , Recently, AgNbO 3 (AN), which displays the large polarization up to 52 μC/cm 2 , has become a hot topic . Massive efforts have been made to optimize its energy density via stabilizing the AFE phase ,− and improving the E b . − For the former, it has been the most active field in AN ceramics and two methods have been widely utilized: (i) decreasing the tolerance factor ( R A , R B , and R O represent the ionic radii of A-, B-site cation, and oxygen anion, respectively) by introducing ions with smaller (larger) radii at A-(B-) sites, such as Bi 3+ , La 3+ , ,,, Sr 2+ , Sm 3+ , and so on and (ii) reducing the polarizability of B-site cations, such as replacing Nb 5+ (3.1 Å 3 ) with Ta 5+ (2.82 Å 3 ) and W 6+ (2.5 Å 3 ). ,, After the modulation, the W rec has grown from ∼2 J/cm 3 of pristine AN ceramics up to 7.01 J/cm 3 of La-modified AN ceramics. , For the latter, E b could be enhanced by decreasing the grain size , and/or reducing the ceramic thickness because E b follows the exponential decay relationship with either the grain size or the thickness . It is of importance to note that the multilayer ceramic capacitors (MLCCs) could intergrate the merits of the stabilized AFE phase and improved E b by optimizing the composition and thickness of the monolayer .…”

Greatly enhanced energy storage and discharge properties of AgNbO3 ceramics with a stable antiferroelectric phase and high breakdown strength using hydrothermally synthesized powders

“…4(k) shows E b and energy storage performances of recently reported pure AgNbO 3 ceramics. 3,4,10,11,13,[26][27][28][29][30][31][32][33][34][35][36] Clearly, hydrothermally fabricated AgNbO 3 ceramics exhibit obvious advantages in terms of E b , W rec and h. Therefore, it is proved that the strategy proposed in this work to improve the energy storage capacity of AgNbO 3 ceramics is effective.…”