Preparation of Agglomerate-Free and Highly Crystalline (Ba0.5, Sr0.5)TiO3 Nanoparticles by Salt-Assisted Spray Pyrolysis

Abstract

YÁ¬ ¶Mªð@j½»ï_Ìae¡ÜµÄé｡ÜAEʱqm¬ É¡ÀjERìvv Låwåw@Hw¤È¨¿»wVXeêUC7398527 Ls¾R 141Optimum conditions for the synthesis of nonagglomerated barium strontium titanate (BST) nanoparticles were examined. The eects of salt concentration, operating temperature, and droplet/particle residence time in the hot zone as a function of carrier gas ow rate and heating zones on particle size, crystallinity, and chemical composition of BST nanoparticles were investigated. Highly crystalline, dense BST nanoparticles in a size range of 1760 nm with a narrow size distribution (s g 1.2) were prepared using a saltassisted spray pyrolysis (SASP) method without the need for postannealing or for controlling of initial excess of barium and strontium in the solution, relative to titanium. The particle size decreased with decreasing salt concentration, operating temperature and droplet/particle residence time in the hot zones. The chemical homogeneity of the resulting particles was analyzed using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICPAES). The chemical composition of the resulting powder completely reected the initial solution composition. SASP can be used to produce highly crystalline (Ba 1|x , Sr x )TiO 3 ( x0.5) nanoparti cles in sizes as small as 30 nm in a single step.

Design of particles by spray pyrolysis and recent progress in its application

“…They proposed a salt-assisted spray pyrolysis in which primary particles are dispersed in a salt matrix and nanometer particles of agglomeration-free are formed after dissolution of salt [131]. They produced bioceramics [55], ZnO [56], Ba 0.5 Sr 0.5 TiO 3 [57], and BaTiO 3 [58]. Ga 2 O 3 , produced by salt-assisted spray pyrolysis, was shown to be converted into GaN nanoparticles under ammonia gas [18].…”

Synthesis of Pure, Crystalline (Ba,Sr)TiO3 Nanosized Powders in Radio Frequency Induction Thermal Plasma

“…In the synthesis of BaTiO 3 nanosize particles in RF induction plasma, the use of vapor phase precursors showed the difficulty to adjust the chemical composition of products and avoid the impurity phase formation 26 . In the solid solution system, (Ba,Sr)TiO 3 , it is more difficult to obtain impurity‐free nanoparticles, and careful consideration was given to choose an appropriate precursors in the synthesis of (Ba 0.5 ,Sr 0.5 )TiO 3 nanoparticles by a spray pyrolysis method 27 …”

“…26 In the solid solution system, (Ba,Sr)TiO 3 , it is more difficult to obtain impurity-free nanoparticles, and careful consideration was given to choose an appropriate precursors in the synthesis of (Ba 0.5 ,Sr 0.5 )TiO 3 nanoparticles by a spray pyrolysis method. 27 The liquid precursors were prepared by mixing three different solutions (solutions 1-3). A total of 0.0125 mol (4.38 g) of titanium tetra-n-butoxide (TTBO) (Ti(OC 4 H 9 ) 4 , 97.0%, Kanto Chemical, Tokyo, Japan) was added to 0.050 mol (5.25 g) of diethanolamine (DEA) ((HOCH 2 CH 2 ) 2 NH, 99.0%, Kanto Chemical) under magnetic stirring to obtain a clear solution (solution 1).…”

Atomic spectrometry update. Industrial analysis: metals, chemicals and advanced materials

“…Agglomerate free and highly crystalline barium strontium titanate (BST) ceramic nanoparticles have been prepared by Itoh and Okuyama using the salt assisted spray pyrolysis method. 270 The effects of the salt concentration, operating temperature and droplet/particle residence time in the hot zone as a function of carrier gas flow rate on the particle size, crystallinity and chemical composition of the particles were evaluated. It was found that particle size decreased with decreasing salt concentration, operating temperature and residence time.…”