DOPANT EFFECTS ON THE STRUCTURAL, OPTICAL AND ELECTRICAL TRANSPORT PROPERTIES IN SrTi1-xCoxO3 NANOPARTICLES SYNTHESIZED BY SOL–GEL METHOD

2010 ◽  
Vol 19 (02) ◽  
pp. 219-227
Author(s):  
DOAN THI THUY PHUONG ◽  
NGUYEN VAN MINH
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Annealing Temperature ◽  
Dopant Concentration ◽  
Sol Gel ◽  
Average Particle Size ◽  
Average Particle ◽  
Electrical Transport Properties ◽  
Gel Method ◽  
Sol Gel Method

We investigate effects of Co dopant concentration on the structure, as well as optical and electrical transport properties in SrTi 1-x Co x O 3 (x = 0.00, 0.10, 0.20, 0.30, 0.40, 0.50) nanoparticles prepared by sol–gel method with annealing temperature considerably lower than that employed conventionally. The dopant-induced changes are studied by XRD, Raman, Optical absorption and Impedance measurements. The results show an average particle size of about 30 nm, and decreasing lattice parameters. In the Raman spectra, a broad structure in the region 200–500 cm-1 is almost absent and the peaks in the region 600–800 cm-1 show different relative weights with respect to those from SrTiO 3, which is related to structural changes, decreasing gap with increasing dopant concentration in conjuction with increasing grain boundary contribution to the impedance. These results also demonstrate the feasibility of synthesizing the compound with low annealing temperature.

scholarly journals Magnetic and Electrical Transport Properties of Double Perovskite Sr2FeMoO6Prepared by Sol-Gel Method

2011 ◽  
Vol 8 (s1) ◽  
pp. S189-S194 ◽  
Author(s):  
Yong-Qing Zhai ◽  
Jing Qiao ◽  
Zhang Zhang
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Room Temperature ◽  
Sol Gel ◽  
Double Perovskite ◽  
Reducing Agent ◽  
Perovskite Oxide ◽  
Electrical Transport Properties ◽  
Gel Method ◽  
Sol Gel Method

With activated carbon for reducing agent, the sol-gel method was used to prepare the giant magnetoresistance materials Sr2FeMoO6, which is the double Perovskite oxide. The structure, morphology, magnetic and electrical transport properties were investigated respectively by x-ray diffraction, scanning electron microscopy and vibrating sample magnetometer. The as-synthesized sample is Sr2FeMoO6with tetragonal crystal structure and I4/mmm space group and unit cell parameter is a = 5.580Å, c = 7.882Å. The primary particles are spherical in shape and the grain size is below 100 nm. The curie temperature is above room temperature and the saturation magnetization is 13.321 A·m2/kg under 1.0 T at room temperature. The sample exhibit typical semiconductor behavior and the conductive mechanism can be described by small polaron variable range hopping model. The room temperature magnetoresistance of the sample under 1.0 T field is up to -10.02%. Moreover, it is found the dosage of citric acid and the amount of reducing agent has great effect on the phase structure and magnetic properties of the samples.

scholarly journals Structure and dielectric behaviour of Sr-modified Bi4Si3O12 thin films prepared via sol gel method

2018 ◽  
Vol 12 (1) ◽  
pp. 36-44 ◽  
Author(s):  
Abbas Sadeghzadeh-Attar ◽  
Saeid Hajijafari-Bidgoli ◽  
Mohammad Bafandeh
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Dielectric Loss ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Average Particle Size ◽  
Average Particle ◽  
Sem Images ◽  
Gel Method ◽  
Sol Gel Method

Bismuth silicate (Bi4Si3O12, BSO) nanostructured films containing 0,1,2, and 3mol% Sr were prepared via sol-gel method and annealed at different temperatures up to 700?C. The effects of Sr content on the structure and morphology of prepared films were investigated. SEM images showed that surfaces of the prepared films were dense, smooth and homogeneous. The average particle size was changed from 30 to 35 nm as the annealing temperature was increased from 500 to 700?C. Variation of the dielectric constant and dielectric loss as a function of frequency and annealing temperature for the synthesized thin films with different content of Sr were also studied. The dielectric constant and dielectric loss decrease with Sr addition, and reach the minimum for the sample containing 2mol% Sr. These changes could be attributed to the crystal structure and formation of secondary phases.

Barium Zirconium Titanate Powders Prepared by Sol–Gel Method

2011 ◽  
Vol 412 ◽  
pp. 86-89 ◽  
Author(s):  
Xiao Ling Deng ◽  
Dong Jiao Guo ◽  
Wei Cai ◽  
Chun Lin Fu
Keyword(s):  
Sol Gel ◽  
Average Particle Size ◽  
Average Particle ◽  
Gravimetric Analysis ◽  
Zirconium Titanate ◽  
Thermal Gravimetric ◽  
Gel Method ◽  
Sol Gel Method ◽  
Barium Zirconium Titanate ◽  
Xrd Patterns

Barium zirconium titanate, Ba (Zr0.20Ti0.80)O3(BZT) powders were prepared by sol-gel method. These powders were characterized by thermal gravimetric and differential thermal gravimetric analysis (TG-DTA), X-ray diffraction (XRD). The grain size and lattice constant were determined. The decomposition of the precursors was monitored by TG-DTA. XRD patterns reveal that BZT powders heat-treated at 800°C present single phase with perovskite type cubic structure. The average particle size of the BZT powders is about 25 nm.

Synthesis and Characterization of Nanosized ZrTiO4 Powders Prepared by the Sol-Gel Method

2006 ◽  
Vol 530-531 ◽  
pp. 401-407 ◽  
Author(s):  
I.C. Cosentino ◽  
F.M. Vichi ◽  
E.N.S. Muccillo ◽  
R. Muccillo
Keyword(s):  
Mercury Porosimetry ◽  
Sol Gel ◽  
Average Particle Size ◽  
Nitrogen Adsorption ◽  
Zirconium Oxychloride ◽  
Average Particle ◽  
Titanium Tetraisopropoxide ◽  
Nanosized Powders ◽  
Gel Method ◽  
Sol Gel Method

Ceramic ZrTiO4 powders were prepared by a modified sol-gel method using zirconium oxychloride and titanium tetraisopropoxide. In situ high temperature X-ray diffraction results show that crystallization of the amorphous gel starts at 400 °C. Singlephase ZrTiO4 nanoparticles were obtained after heat treatment at 450 oC for 1 h. An average particle size of 46 nm has been determined by nitrogen adsorption analysis. After pressing these sinteractive powders, pellets with controlled pore size distribution were obtained by sintering at temperatures as low as 400 oC. The analysis of pores by mercury porosimetry shows an average porosity of 45 %. Pressing and sintering the nanosized powders prepared by that modified sol-gel technique produced pellets that are good candidates to be used in humidity sensing devices.

Mössbauer Investigation of γ-Fe2O3 Nanocrystals in Silica Matrix Prepared by the Sol-gel Method

2002 ◽  
Vol 57 (3-4) ◽  
pp. 154-158 ◽  
Author(s):  
C. Cannas ◽  
G. Concas ◽  
F. Congiu ◽  
A. Musinu ◽  
G. Piccaluga ◽  
...  
Keyword(s):  
Particle Size ◽  
Low Temperature ◽  
Sol Gel ◽  
Average Particle Size ◽  
Volume Ratio ◽  
Silica Matrix ◽  
Blocking Temperature ◽  
Average Particle ◽  
Gel Method ◽  
Sol Gel Method

A series of Fe2O3-SiO2 nanocomposites (25 weight % of Fe2O3) has been prepared using a sol-gel method. Samples showing different features were obtained by varying the evaporation conditions acting on the surface / volume ratio of the starting sol. The samples were investigated using Mössbauer spectroscopy at low temperature. The Fe2O3 nanoparticles have been identified as maghemite ( γ-Fe2O3) particles. The samples show a superparamagnetic behavior with a blocking temperature that depends on the average particle size.

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