Electrical investigations of holmium-doped BaTiO3 derived from sol-gel combustion

2010 ◽  
Vol 25 (6) ◽  
pp. 1057-1063 ◽  
Author(s):  
Marin Cernea ◽  
Carmen Galassi ◽  
Bogdan S. Vasile ◽  
Paul Ganea ◽  
Roxana Radu ◽  
...  

Holmium-doped BaTiO3 with composition Ba0.97Ho0.03TiO3 was prepared by sol-gel combustion method. A molar ratio of citrate/nitrate (CA/NO3− = 1.3) was used to prepare nanopowders of (Ba,Ho)TiO3. The structure and microstructure of (Ba,Ho)TiO3 powders and ceramics were investigated. The ceramics exhibit a dielectric constant of about 4400 and dielectric loss (tan δ = 0.267) at 10 Hz, and at the Curie temperature (Tc = 132 °C). The remanent polarization and the coercive field of Ba0.97Ho0.03TiO3 ceramics, at 1 kHz, were Pr = 6 μC/cm2 and EC = 0.75 kV/cm. The dielectric and ferroelectric behavior of the holmium-doped BaTiO3 is influenced by the amphoteric character of Ho3+ ions.

2013 ◽  
Vol 802 ◽  
pp. 149-153
Author(s):  
Chanyaphak Thongchanthep ◽  
Sarawut Thountom

The ferroelectric ceramic, Barium Strontium Tinanate (Ba0.7Sr0.3TiO3), was prepared by the sol-gel combustion method using citric acid, urea, and glycine as the fuel for reduce the calcination temperature. The molar ratio of sol powderto fuel was 1:1. All of the samples were calcined at 450, 550, 650, 750, 850 and 950°C for 2 h. Then,Ba0.7Sr0.3TiO3powders were applied with acid treatment process. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscope (TEM) analysis were used to characterize the crystal structure and microstructure. The perovskite phases of BST and the pyrochlore (BaCO3,SrCO3) were obtained after the calcinations temperature of 550°C. BST powders were applied with acid treatment process.The XRD result showed the pure perovskite phase without the phase of pyrochlore in all of the samples. Ba0.7Sr0.3TiO3was in cubic structure, corresponding to JCPDS 34-0411. SEM analysis of BST powders calcined at 750°C.The particles were spherical morphology and had agglomerates while the particles sizes were larger corresponding with the increase of calcinations temperature.The results for TEM analysis of the BST powders prepared by using urea as the fuel had a smaller particles,and the average of particle size was about 47 nm.


2014 ◽  
Vol 185 ◽  
pp. 86-91 ◽  
Author(s):  
Alexandre R. Bueno ◽  
Renata F.M. Oman ◽  
Paula M. Jardim ◽  
Nicolás A. Rey ◽  
Roberto R. de Avillez

2018 ◽  
Vol 526 (1) ◽  
pp. 187-192 ◽  
Author(s):  
S. B. Bankar ◽  
N. S. Meshram ◽  
N. N. Sarkar ◽  
H. S. Ahamad ◽  
S. J. Dhobale ◽  
...  

2019 ◽  
Vol 33 (10) ◽  
pp. 1950081 ◽  
Author(s):  
Madeeha Riaz ◽  
Rehana Zia ◽  
Snudia Aslam ◽  
Alliya Qamar ◽  
Tousif Hussain ◽  
...  

In this paper, low temperature, economical sol–gel combustion method was adopted to synthesize wollastonite ceramic. Calcium nitrate tetrahydrate and tetraethyl orthosilicate were taken as source for Ca and Si, while citric acid and nitric acid were used as chelating/combustion agents. The yielded powder calcined at 600[Formula: see text]C for 4 h was characterized by FTIR, XRD and SEM techniques. Results showed that the citrate combustion method was the most efficient method to prepare wollastonite at low temperature. Moreover, in vitro bioactivity test performed in simulated body fluid (SBF) showed good bioactivity of synthesized wollastonite ceramics.


2013 ◽  
Vol 455 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Phiram Panthong ◽  
Thanawat Klaytae ◽  
Kanok Boonma ◽  
Sarawut Thountom

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