Synthesis and Properties of (Bi0.5Na0.5)TiO3 Powders by Hydrothermal Method

2007 ◽  
Vol 336-338 ◽  
pp. 140-142
Author(s):  
Jun Jie Hao ◽  
Xiao Hui Wang ◽  
Shi Yun Lin ◽  
Long Tu Li
Keyword(s):  
Particle Size ◽  
Hydrothermal Method ◽  
Single Phase ◽  
Piezoelectric Ceramics ◽  
Treatment Temperature ◽  
Lead Free ◽  
Excellent Candidate ◽  
Traditionally Prepared ◽  
Particle Size And Morphology ◽  
Size And Morphology

Na0.5Bi0.5TiO3 (NBT) is considered to be an excellent candidate for lead-free piezoelectric ceramics. In this study, we propose a hydrothermal method for the preparation of single phase NBT powder at relatively low treatment-temperature. The particle size and morphology of the synthesized powders were examined by SEM. The powders were further pressed into disk and sintered at 1120°C/2h in air, and its properties and microstructure were compared with traditionally prepared samples.

scholarly journals Synthesis of Nanocrystalline Barium-Hexaferrite from Nanocrystalline Goethite Using the Hydrothermal Method: Particle Size Evolution and Magnetic Properties

1996 ◽  
Vol 432 ◽  
Author(s):  
R. L. Penn ◽  
J. F. Banfield ◽  
J. Voigt
Keyword(s):  
Particle Size ◽  
Hydrothermal Method ◽  
Treatment Time ◽  
Barium Hexaferrite ◽  
Threshold Size ◽  
New Synthesis ◽  
Magnetization Saturation ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Equilibrium Morphology

AbstractTo characterize particle size/magnetic property relationships, 9 to 50 nm in diameter barium hexaferrite, BaFe12O19 (BHF), particles were prepared using a new synthesis route. By replacing the conventional 50 to 100 nm particles of goethite with nanocrystalline goethite produced via the microwave anneal method of Knight and Sylva [1], nanocrystalline BHF was synthesized using the hydrothermal method. Evolution of particle size and morphology with respect to concentration and heat treatment time is reported. Hysteresis properties, including coercivity (0.2 – 1.0 kOe), magnetization saturation (0.1 – 33.4 emu/g), and magnetization remanence (0.004 – 22.5 emu/g) are discussed as a function of particle size. The magnetization saturation and remanence of the 7 nm particles is nearly zero, suggesting the superparamagnetic threshold size for BHF is around this size. In addition, the equilibrium morphology of BHF crystals was calculated to be truncated hexagonal prisms which was verified by experiment, and the isoelectric point, pH of 4.1, was measured for 18 nm BHF particles.

CONTROL OF PARTICLE SIZE AND MORPHOLOGY OF COBALT-FERRITE NANOPARTICLES BY SALT-MATRIX DURING ANNEALING

2012 ◽  
Vol 05 ◽  
pp. 177-181
Author(s):  
A. AZIZI ◽  
S.K. SADRNEZHAAD ◽  
M. MOSTAFAVI
Keyword(s):  
Particle Size ◽  
Single Phase ◽  
Cobalt Ferrite ◽  
Average Particle Size ◽  
Average Particle ◽  
Mechanically Alloyed ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Full Annealing ◽  
Salt Matrix

Salt-matrix annealing of mechanically alloyed Co -ferrite nanopowder was used to modify its particle size and morphology. Efficiency improvement due to suppression of sintering and growth resulted in reduction of average particle size from ~100nm for salt-less to ~40nm for salt-full annealing procedure. Nanosized single-phase cobalt-ferrite particles were observed after 2h annealing at 750°C in the samples milled for 20 hours both with and without NaCl . NaCl:CoFe 2 O 4 ratio of 10:1 resulted in cabbage-like clusters containing particles smaller than ~50 nm.

Direct manipulation of particle size and morphology of ordered mesoporous silica by flow synthesis

RSC Advances ◽  
2015 ◽  
Vol 5 (18) ◽  
pp. 13331-13340 ◽  
Author(s):  
T. N. Ng ◽  
X. Q. Chen ◽  
K. L. Yeung
Keyword(s):  
Particle Size ◽  
Mesoporous Silica ◽  
Hollow Spheres ◽  
Ordered Mesoporous Silica ◽  
Direct Manipulation ◽  
Flow Synthesis ◽  
Precise Control ◽  
Ordered Mesoporous ◽  
Particle Size And Morphology ◽  
Size And Morphology

Flow-synthesis of mesoporous silica allows deliberate and precise control over the size and shapes and enables the preparation of complex microstructures (i.e., hollow spheres).

scholarly journals Dehumidified Air-Assisted Spray-Drying of Cloudy Beetroot Juice at Low Temperature

2021 ◽  
Vol 11 (14) ◽  
pp. 6578
Author(s):  
Aleksandra Jedlińska ◽  
Alicja Barańska ◽  
Dorota Witrowa-Rajchert ◽  
Ewa Ostrowska-Ligęza ◽  
Katarzyna Samborska
Keyword(s):  
Particle Size ◽  
Physicochemical Properties ◽  
Spray Drying ◽  
Low Temperatures ◽  
Beetroot Juice ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Tapped Density ◽  
Lower Loss ◽  
Better Than

This paper discusses the physicochemical properties of powders obtained by spray drying of cloudy beetroot juice, using dehumidified air in variants with or without carriers. The inlet air temperature was 130 °C or 90 °C, and the addition of the carriers was at a ratio of juice to carrier solids of 3:2. In the obtained powders, the following physicochemical properties were determined: water content and water activity, apparent density, loose and tapped density, porosity, flowability, particle size and morphology, and the content and retention of betalains. It was possible to dry cloudy beetroot juice without the use of carriers at low temperatures (90 or 130 °C). The 100% beetroot powders were characterized by satisfactory physicochemical properties, often better than those with carriers (including lower hygroscopicity and higher color saturation and yield). A lower loss of betalains was found for the powders with the addition of carriers. The best process yields were obtained for the powder without carriers at 130 °C and 90 °C.

Particle-size and morphology dependence of the preferred interface orientation in LiFePO4 nano-particles

2014 ◽  
Vol 2 (37) ◽  
pp. 15437-15447 ◽  
Author(s):  
Aziz Abdellahi ◽  
Oncu Akyildiz ◽  
Rahul Malik ◽  
Katsuyo Thornton ◽  
Gerbrand Ceder
Keyword(s):  
Particle Size ◽  
First Principles ◽  
Nano Particles ◽  
Particle Size And Morphology ◽  
Interface Orientation ◽  
Size And Morphology

Using calculations based on first principles, we demonstrate that the preferred interface in singles LiFePO4 particles depends both on the particle size and morphology.

Effect of particle size and morphology on the properties of luminescence in ZnWO4

2014 ◽  
Vol 153 ◽  
pp. 130-135 ◽  
Author(s):  
V.M. Lisitsyn ◽  
D.T. Valiev ◽  
I.A. Tupitsyna ◽  
E.F. Polisadova ◽  
V.I. Oleshko ◽  
...  
Keyword(s):  
Particle Size ◽  
Effect Of Particle Size ◽  
Particle Size And Morphology ◽  
Size And Morphology

scholarly journals Effect of CaCl2 on Microstructure of Calciothermic Reduction Products of Ti2O3 to Prepare Porous Titanium

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 698 ◽  
Author(s):  
Guobo Yang ◽  
Baoqiang Xu ◽  
Heli Wan ◽  
Fengkang Wang ◽  
Bin Yang ◽  
...  
Keyword(s):  
Particle Size ◽  
Uniform Distribution ◽  
Reduction Process ◽  
Porous Titanium ◽  
Surface Zone ◽  
Calciothermic Reduction ◽  
Particle Size And Morphology ◽  
Ti Particles ◽  
Size And Morphology ◽  
Titanium Structure

The compound CaCl2 plays a significant role in the process of direct calciothermic reduction of Ti2O3 to prepare porous titanium. In this paper, the effect of CaCl2 on reduction products by calciothermic reduction of Ti2O3 was investigated. Results show that the distribution of CaCl2 in reduction preform influences particle size and morphology differences in reduction products both on the surface and the inside. The CaCl2 is transferred to the surface of the Ti2O3 preform due to its volatilization before and throughout reduction. The content of CaCl2 in the surface zone of Ti2O3 preform is significantly higher than that in the interior during the reduction process, contributing to the formation of large Ti particles with a smooth shape on the surface, and small Ti particles with inherited morphology of Ti2O3 inside. More CaCl2 causes the aggregation of Ti particles to form large Ti particles which are advantageous as they connect and form a more solid porous titanium structure. The presence of a small amount of CaCl2 in the interior also results in the coexistence of small Ti and CaO particles, forming a loose structure with uniform distribution.

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