Polycrystalline La0.8Sr0.2GaO3 perovskite synthesized by sol–gel process along with temperature dependent photoluminescence

2017 ◽  
Vol 181 ◽  
pp. 1-7 ◽  
Author(s):  
F. Belkhiria ◽  
F.I.H. Rhouma ◽  
S. Hcini ◽  
M. Daoudi ◽  
H. Gammoudi ◽  
...  
2020 ◽  
Vol 557 (1) ◽  
pp. 28-42
Author(s):  
Srinivas Pattipaka ◽  
Sweety Bora ◽  
D. Pamu

The lead-free (1 – x) Bi0.5Na0.5TiO3 – x KNbO3 (BNT-KN; x = 0 – 0.12) composite ceramics have been synthesized by a sol-gel process. Their structure, morphology, AC conductance and dielectric response were studied systematically. The X-ray diffraction patterns of BNT-KN revealed a morphotropic phase boundary between a rhombohedral and a pseudocubic structure. The temperature-dependent dielectric response of pure BNT revealed two-phase transitions at 200 °C (TR-T or Td) and 320 °C (TC). Furthermore, the critical temperatures were found to shift to lower values with increasing KN concentration. The manifested relaxor behavior was well confirmed by a modified Curie – Weiss law. The hopping conduction mechanism in BNT-KN was characterized through AC-resistivity analysis.


2012 ◽  
Vol 503 ◽  
pp. 375-380 ◽  
Author(s):  
Wen Ping Geng ◽  
Xiu Jian Chou ◽  
Yong Bo Lv ◽  
Ji Jun Xiong ◽  
Wen Dong Zhang

(Pb,La)(Zr,Ti)O3antiferroelectric thick films were prepared on Pt (111)/ Ti/SiO2/Si (100) substrates by a sol-gel process. The effects of single annealing and multistep annealing on the structures and electric properties of the films were investigated. The crystal orientation and structure of the antiferroelectric thick films were studied. The thick films by multistep annealing have higher (100)-preferred orientation than them by single annealing. The surface of the films was more smooth, compact and uniform by single annealing. The antiferroelectric nature of the (Pb,La)(Zr,Ti)O3antiferroelectric thick films by various sintering procedures was demonstrated by P(polarization)-E(electric field) and C(capactitance)-E(electric field). The temperature dependent of the dielectric constant and loss was measured under the frequency 1, 10, and 100 kHz and comparing with traditional signal annealing, the films have phase transition from antiferroelectric state to paraelectric state by multistep annealing.


2012 ◽  
Vol 61 (8) ◽  
pp. 1171-1176
Author(s):  
Sang-heon Lee ◽  
Wonshoup So ◽  
Jae Hak Jung ◽  
Giwoong Nam ◽  
Hyunsik Yoon ◽  
...  

2013 ◽  
Vol 668 ◽  
pp. 255-258
Author(s):  
Zou Ming Xu ◽  
Yu Xia Wang

Polysilsesquioxane xerogels have been prepared via hydrolysis and condensation of the sole precursor N-(3-Trimethoxysilylethyl)ethylenediamine (TMSEEDA) with no acid or base catalyzed sol–gel processing. Complex siloxane matrix is formed along with abundant and covalently linked ethylenediamine (EDA). After high temperature thermal treatment over 500 °C, EDA groups are completely decomposed. The as-synthesized sample exhibits strong blue emission at room temperature (RT), which is shifted to green and red bands when encountered high temperature annealing treatment (in air), promising potential applications in opto-electronics and sensor. Moreover, the PL mechanism is also discussed in details.


2008 ◽  
Vol 516 (23) ◽  
pp. 8702-8706 ◽  
Author(s):  
S. Mandal ◽  
M.L.N. Goswami ◽  
K. Das ◽  
A. Dhar ◽  
S.K. Ray

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