Effect of sintering temperature on morphology, dielectric and ferroelectric properties of five layer Aurivillius oxides: A2Bi4Ti5O18 (A=Ba, Pb and Sr) synthesized by co-precipitation route

2017 ◽  
Vol 28 (11) ◽  
pp. 8266-8277 ◽  
Author(s):  
Shivangi Dubey ◽  
Rajnish Kurchania
Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3717
Author(s):  
Jae-Young Jung ◽  
Soung-Soo Yi ◽  
Dong-Hyun Hwang ◽  
Chang-Sik Son

The precursor prepared by co-precipitation method was sintered at various temperatures to synthesize crystalline manganese tungstate (MnWO4). Sintered MnWO4 showed the best crystallinity at a sintering temperature of 800 °C. Rare earth ion (Dysprosium; Dy3+) was added when preparing the precursor to enhance the magnetic and luminescent properties of crystalline MnWO4 based on these sintering temperature conditions. As the amount of rare earth ions was changed, the magnetic and luminescent characteristics were enhanced; however, after 0.1 mol.%, the luminescent characteristics decreased due to the concentration quenching phenomenon. In addition, a composite was prepared by mixing MnWO4 powder, with enhanced magnetism and luminescence properties due to the addition of dysprosium, with epoxy. To one of the two prepared composites a magnetic field was applied to induce alignment of the MnWO4 particles. Aligned particles showed stronger luminescence than the composite sample prepared with unsorted particles. As a result of this, it was suggested that it can be used as phosphor and a photosensitizer by utilizing the magnetic and luminescent properties of the synthesized MnWO4 powder with the addition of rare earth ions.


2015 ◽  
Vol 2 (4) ◽  
pp. 045901 ◽  
Author(s):  
Parmod Kumar ◽  
Rahul Joshi ◽  
Anurag Gaur ◽  
Lalit Kumar ◽  
K Asokan

2014 ◽  
Vol 895 ◽  
pp. 319-322
Author(s):  
Lim Kean Pah ◽  
Abdul Halim Shaari ◽  
Chen Soo Kien ◽  
Chin Hui Wei ◽  
Albert Gan ◽  
...  

In this work, we report the effect of sintering temperature (900°C, 1000°C, 1100°C and 1200°C) on the electrical and magnetotransport properties of polycrystalline La0.67Sr0.33MnO3 (LSMO). Single phase of LSMO hexagonal structure (R-3c) accompanied with minor phases was successfully synthesized by co-precipitation method. With increasing sintering temperature, grain growth was promoted and grain connectivity was improved. It was found that an enhancement of resistivity on smaller grain size was due to larger grain surface over volume (grain boundaries effect). The shifting of the metal-insulator transition (TMI) to higher temperature was also responsible for observed changes in physical properties. TMI of 900°C, 1000°C and 1100°C were 232 K, 278 K and 298 K respectively however 1200°C was out of measurement range (higher than 300 K). In summary, CP900 with smaller grain size distribution (~200 nm) displayed the highest resistivity and MR% of -19.2% (at 80 K, 10 kG).


2006 ◽  
Vol 21 (1) ◽  
pp. 119-124 ◽  
Author(s):  
A.I.Y. Tok ◽  
L.H. Luo ◽  
F.Y.C. Boey ◽  
J.L. Woodhead

Gd-doped ceria solid solutions have been recognized to be leading electrolytes for use in intermediate-temperature fuel cells. In this paper, the preparation, solubility, and densification of Gd0.1Ce0.9O1.95 ceramics derived from carbonate co-precipitation are reported. The dissolution of Gd2O3 in CeO2 lattice was identified to be completed during the co-precipitation process by studying the lattice parameter as a function of temperature. After calcination at 800 °C for 2 h, the nano-sized Gd0.1Ce0.9O1.95 powder (∼33 nm) with a nearly spherical shape and a narrow particle-size distribution was obtained. This calcined powder has high sinterability and maximum densification rate at ∼1000 °C. Sintering at 1300 °C for 4 h yielded over 97% relative density with near maximum. The grain size increased with increases in sintering temperature. The ionic conductivity of these pellets was tested by alternating current impedance spectroscopy to elucidate the contribution of intragranular and intergranular conductivity to the total ionic conductivity. It was found that sintering temperature does not affect intragranular conductivity, though intergranular conductivity was strongly influenced by grain size, grain boundary area, and relativity density. This pellet sintered at 1500 °C for 4 h showed a high ionic conductivity of 5.90 × 10−2 s/cm when measured at 750 °C. The characterization and structural evaluation of the as-received powders were carried out using x-ray diffraction, transmission electron microscopy, Brunauer–Emmett–Teller, and dilatometer and impedance analysis.


2007 ◽  
Vol 358 (1) ◽  
pp. 35-41
Author(s):  
Piyachon Ketsuwan ◽  
Athipong Ngamjarurojana ◽  
Yongyut Laosiritaworn ◽  
Supon Ananta ◽  
Rattikorn Yimnirun

2006 ◽  
Vol 05 (02n03) ◽  
pp. 265-271
Author(s):  
MENG KUI WANG ◽  
YU QIANG YANG

The preparing process and the properties of thick-film double-based thermo-sensitive material were studied. The preparing steps were as follows: (i) preparing Ba 1-x Sr x TiO 3 micro-powders with chemical co-precipitation method; (ii) adding dispersants and surface active agents into crushing medium powders to prepare Ba 1-x Sr x TiO 3 nanopowders; (iii) preparing V 2 O 3-based micro-powders; (iv) mixing Ba 1-x Sr x TiO 3 nanopowders, V 2 O 3-based micro-powders, donor impurities, acceptor impurities and micro additives according to a certain ratio to make thick-film thermo-sensitive ceramic material. The presintering and sintering temperature of the prepared PTC ceramics were both reduced, which is very meaningful in using cheaper SiC instead of more expensive MoSi 2, prolonging the kiln's life, and lowering the production cost. The samples we prepared did not contain PbO , so they are safe to the environment.


2015 ◽  
Vol 804 ◽  
pp. 34-37
Author(s):  
Tanabat Promjun ◽  
Yongyut Manjit ◽  
Saksit Sukprasong ◽  
Athipong Ngamjarurojana

This research was conducted to improve the ferroelectric properties of PZT based ceramics by studying the effect of sintering conditions in terms of temperature and soaking time (time of sintering) on the ferroelectric properties of ceramics in the 0.8Pb (Zr1/2Ti1/2)O3-0.2Pb (Zn1/3Nb2/3)O3 system prepared by vibro-milling mixed-oxide method. The XRD patterns of specimens showed perovskite structure for all compositions. The pyrochlore phase was not observed in this system. The sintering temperature and soaking time affects the ferroelectric properties of ceramics by the optimum sintering condition for 0.8PZT-0.2PZN ceramic is sintered at 1250°C for 2h.


2011 ◽  
Vol 01 (01) ◽  
pp. 119-125 ◽  
Author(s):  
W. CHEN ◽  
C. X. HUANG ◽  
T. S. YAN ◽  
W. ZHU ◽  
Z. P. LI ◽  
...  

CoFe 2 O 4/ Pb ( Zr 0.53 Ti 0.47) O 3 (abbreviated as CFO/PZT) multiferroic composite thick films were successfully fabricated on alumina substrate with gold bottom electrode by screen printing method at a low-sintering temperature. The processing included the modification and dispersion of ferromagnetic CFO powder and ferroelectric PZT powder, the preparation of uniform pastes, and the selection of proper annealing temperature for composite thick films. Transmission electron microscopic pictures (TEM) indicated the submicron meter of particles size for both CFO and PZT particles. After annealing at 900°C for 1 h in air, tape test confirmed the quality of multiferroic thick films as well as pure CFO and PZT films. X-ray diffraction (XRD) showed a coexistence of CFO and PZT phases; furthermore, a smooth surface was observed through scanning electron microscopic (SEM) pictures along with the sharp cross-sectional picture, indicative of 100 μm of film thickness. Ferromagnetic and ferroelectric properties were observed in CFO/PZT films simultaneously at room temperature. Compared with the reported CFO/PZT multiferrroic thin films, the present ferromagnetic property was closing to that of the chemical sol-gel synthesized film and even that from the physical pulsed laser deposition technique. However, the ferroelectric property showed a degenerated behavior, possible reasons for this was discussed and further optimization was also proposed for the potential multifunctional application.


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