Kinetics and mechanism of solid state reactions of silver tungstate with mercuric bromide and mercuric chloride

Cluster Coordination and Photoluminescence Properties of α-Ag2WO4 Microcrystals

“…However, this suspension and white precipitate were processed in a stainless autoclave at 140°C for 1 h under a constant 4.5 bar pressure. All of these experimental conditions facilitated stoichiometric chemical reactions (2Ag + + WO 4 2− ions) that were responsible for the formation of crystalline α-Ag 2 WO 4 microcrystals, as shown in eqs 1−3.…”

“…The procedure for the typical α-Ag 2 WO 4 microcrystal synthesized by the SC method is described as follows: 1 × 10 −3 mol of tungstate(VI) sodium dihydrate (Na 2 WO 4 ·2H 2 O; 99.5% purity, Sigma-Aldrich) and 2 × 10 −3 mol of silver(I) nitrate (AgNO 3 ; 99.8% purity, Sigma-Aldrich) were dissolved separately in two plastic tubes (Falcon) with 50 mL of deionized water in each tube, and both of the solutions were at pH 6. The first solution with Na + and WO 4 2− ions was transferred to a 250 mL glass beaker (Boeco, Germany, boro 3.3). Then the second solution at room temperature containing 50 mL of Ag + and NO 3 − ions was added to the glass beaker of solution containing the WO 4 2− ions; after some seconds, a yellow suspension appeared and a white precipitate rapidly formed.…”

“…The first solution with Na + and WO 4 2− ions was transferred to a 250 mL glass beaker (Boeco, Germany, boro 3.3). Then the second solution at room temperature containing 50 mL of Ag + and NO 3 − ions was added to the glass beaker of solution containing the WO 4 2− ions; after some seconds, a yellow suspension appeared and a white precipitate rapidly formed. This suspension was ultrasonicated for 1 h in a Branson (model 1510) ultrasonic cleaner with a frequency of 42 kHz.…”

“…In the past, silver tungstate (α-Ag 2 WO 4 ) ceramics and crystals were initially prepared by different preparation methods such as an oxide mixture or solid-state reaction, − precipitation/calcination at elevated temperatures, as well as with a crystal growth process named “Czochralski” . However, these synthetic methods require high temperatures, longer processing times, and sophisticated equipment with high maintenance costs in addition to the formation of deleterious phases and produce crystals of inhomogeneous sizes and shapes.…”

Dielectric Behavior of α-Ag2WO4 and its Huge Dielectric Loss Tangent

“…10,11,16,29,33 . The preparation of α-Ag 2 WO 4 has been successfully carried out by several methods which include solid state reaction [34][35][36] , co-precipitation 22,37-39 , laser ablation in liquid (LAL) 18 , hydrothermal 19,[21][22][23][24][25][26][27]29,[40][41][42] , sonochemical 22,28 and microemulsion 22 methods. Despite the large number of synthesis methods available, it has been a challenge to obtain a fully stable α-Ag 2 WO 4 structure.…”