Improving the Crystallinity and Purity of Monodisperse Ag Fine Particles by Heating Colloidal Sprays In-Flight

Abstract

This work demonstrated the production of highly crystalline, monodisperse fine metal particles with high density and purity using a simple, facile rapid spray heating process. In this technique, a starting solution including fine Ag particles, prepared using a liquid phase method, is sprayed into a horizontal furnace. After this spray heating step, the crystallinity and purity of the particles are greatly improved relative to those of the initial particles, while the morphology and size distribution are maintained. Consequently, the volume resistivity of the Ag particles is decreased from 6.4 × 10–3 Ω·cm (before spray heating) to 3.6 × 10–5 Ω·cm (after spray heating at 500 °C). Detailed analyses show that this significant increase in conductivity results from the improved crystallinity, purity, and density of the material. The rapid spray heating method proposed in this research could be applied to other metals with the potential to produce high-quality fine metal particles.

Effective Factor on Catalysis of Niobium Oxide for Magnesium

“…An understanding of these factors is essential so that the contribution of physical properties can be suppressed. The spray pyrolysis method is promising for producing fine particles because it is a simple, rapid, and continuous process and can be used to fabricate diverse materials with controllable sizes and compositions. − Particles produced by conventional spray pyrolysis are highly uniform in size and chemical composition with a spherical shape and have agglomeration-free states because of the microscale reactions that proceed inside a droplet. Using the spray pyrolysis method, the physical properties of catalysts can be controlled, which is expected to lead to an essential understanding of the catalysis mechanism.…”

DC bias characteristic enhancement of the powder core by using densified submicron sized FeNi particles through spray pyrolysis

“…All the samples revealed ferromagnetic characteristics and had similar saturation magnetic flux density (B s ) values of 1.5 T. This B s value was close to the theoretical B s value for FeNi materials (1.5 T), 20 which proved that the FeNi particles generated by spray pyrolysis route exhibit high purity and crystallinity. 21,22 Furthermore, the coercivity of S12-5.0, S12-2.5, and S12-1.3 was 0.01, 0.009, and 0.01 kOe (0.8, 0.7, and 0.8 kA m À1 ), which is much lower than that of the FeNi powder with no L1 0 phase reported before (14.5 kA m À1 ). 23 Because the hysteresis loss of the core is related to the coercivity value, this low result implies that the FeNi particles are unlikely to affect it.…”

Spherical submicron YAG:Ce particles with controllable particle outer diameters and crystallite sizes and their photoluminescence properties

“…Our previous studies 4, [14][15][16][17][18][19][20][21][22][23][24][25] reported the methods for preparing submicron particles with controllable particle outer diameters and crystallinities. Here, the purpose of this study was to demonstrate the synthesis route for the preparation of spherical submicron yttrium aluminum garnet (YAG):Ce particles with controllable particle outer diameters and crystallite sizes using a ame-assisted spray-pyrolysis method followed by the annealing process.…”

“…17,38 The produced particles are uniform in particle outer diameter, agglomerationfree product, and spherical-shaped particles. 21 The spray pyrolysis is a rapid process, and the reaction occurs in the micron scales, which takes place in small droplets, allowing the produced particles in submicron to micrometer range. 16,18 As a continuation of our previous study, 4 synthesizing PL particles using the spray-pyrolysis, here the focus of this study was to demonstrate the use of ame-assisted spray pyrolysis followed with the annealing process method for producing spherical submicron YAG:Ce particles and to evaluate the correlation of particle outer diameter, crystallite size, and PL performance of the prepared particles.…”

“… 17,38 The produced particles are uniform in particle outer diameter, agglomeration-free product, and spherical-shaped particles. 21 The spray pyrolysis is a rapid process, and the reaction occurs in the micron scales, which takes place in small droplets, allowing the produced particles in submicron to micrometer range. 16,18 …”