I. Order–disorder transitions and solid state reaction kinetics in Na2SO4–K2SO4 system

1983 ◽  
Vol 61 (3) ◽  
pp. 594-598 ◽  
Author(s):  
M. Sunitha Kumari ◽  
Etalo A. Secco

The physicochemical aspects of the order–disorder phase transitions occurring in the Na2SO4–K2SO4 system were investigated by thermal analyses, infrared absorption, and X-ray diffraction methods.Kinetic and structural studies on the compounds KNaSO4 and K3Na(SO4)2 are reported in more detail.

2012 ◽  
Vol 512-515 ◽  
pp. 158-161 ◽  
Author(s):  
Ling Dai ◽  
Qiang Xu ◽  
Shi Zhen Zhu ◽  
Ling Liu

As a new candidate material for the ceramic layer in thermal barrier coatings (TBCs) system, La3NbO7 was synthesized with La2O3 powder and Nb2O5 powder by solid state reaction. The stating powders with a mole ratio of La to Nb of 3:1 were mixed and then the mixture was calcined under the different temperatures(800°C, 1000°C, 1200°C) and dwell times(2h, 6h, 10h). The phase structure of the powder was observed by X–ray diffraction(XRD), and the microstructure of the sample was observed by scanning electron microscope(SEM). The effect of calcination temperature and dwell Time on the phase formation were examined. The results indicate that the La3NbO7 powder with single phase can be synthesized successfully at 1200°C for 10h in air, and the La3NbOsub>7 powders synthesized have an ultra-fine particle size of 0.5˜1µm with a granular particle shape. With the temperature increasing, LaNbO4/sub> was synthesized firstly and then La3NbO7 was synthesized with a mole ratio of La2O3 to LaNbO4 of 1:1.


Author(s):  
Hongqiang Cui ◽  
Yongze Cao ◽  
Lei Zhang ◽  
Yuhang Zhang ◽  
Siying Ran ◽  
...  

Er3+ with different concentrations doped K2Yb(PO4)(MoO4) phosphors were prepared by a solid-state reaction method, and the layered orthorhombic crystal structure of the samples was confirmed by X-ray diffraction (XRD). Under...


2021 ◽  
Vol 321 ◽  
pp. 23-27
Author(s):  
Simona Ravaszová ◽  
Karel Dvořák

The paper is focused on one of the most important component of Portland clinker-on the tricalcium silicate. The study reported in this article is focuses on the changes in crystallite size of synthetic tricalcium silicate obtained using solid state reaction method. Crystallite size changes are monitored during the grinding in three types of laboratory mills in two different conditions. Changing in crystallite size at various grinding time up to 120 minutes are studied with the aid of X-ray diffraction and using the Scherrer equation. It has been found that the most efficient laboratory mill in terms of speed and fineness of the material was the planetary mill.


2019 ◽  
Vol 4 (4) ◽  
Author(s):  
Alpi Zaidah

Pembuatan sampel barium stronsium titanat (BaxSr1-xTiO3) telah dilakukan dengan metode solid state reaction. Variasi komposisi mol Ba(x) untuk pembuatan sampel adalah x=0,4;0,3 dan 0,2. Sampel di-sintering pada suhu 1100oC dengan holding time 2 jam. Karakterisasi sampel dilakukan menggunakan peralatan X-Ray Diffraction (XRD) untuk mengetahui tingkat kekristalan dan ukuran kristal dari sampel. Sedangkan untuk mengetahui besarnya konstanta dielektrik menggunakan RLC-Meter.  Berdasarkan analisa dengan software GSAS, parameter kisi BaxSr1-xTiO3 yang sintering pada suhu 1100°C untuk x=0,4 adalah a=b=c=3,947 nm. Parameter kisi a=b=c=3,947 nm untuk x=0,3, dan parameter kisi a=b=c=3,939 nm untuk x=0,2. Nilai parameter kisi a=b=c menunjukkan struktur kristal berbentuk kubik. Ukuran kristal berturut-turut untuk x=0,4;0,3 dan 0,2 adalah 65 nm, 66 nm dan 69 nm. Ukuran kristal semakin besar seiring dengan meningkatnya penambahan Sr. Pengukuran konstanta dielektrik (K) dilakukan pada rentang frekuensi 1 kHz. Nilai K sampel dengan x=0,4;0,3 dan 0,2 masing-masing sebesar 265, 277 dan 307.


1984 ◽  
Vol 62 (6) ◽  
pp. 1227-1228
Author(s):  
M. Sunitha Kumari ◽  
Etalo A. Secco. I

not available


2014 ◽  
Vol 6 (2) ◽  
pp. 217-231 ◽  
Author(s):  
F. Khatun ◽  
M. A. Gafur ◽  
M. S. Ali ◽  
M. S. Islam ◽  
M. A. R. Sarker

The lithium-cobalt oxide LixCoO2 is a promising candidate as highly active cathode material of lithium ion rechargeable batteries. The crystalline-layered lithium cobaltite has attracted increased attention due to recent discoveries of some extraordinary properties such as unconventional transport and magnetic properties. Due to layered crystal structure, Li contents (x) in LixCoO2 might play an important role on its interesting properties. LiCoO2 crystalline cathode material was prepared by using solid-state reaction synthesis, and then LixCoO2 (x<1) has been synthesized by deintercalation of produced single-phase powders. Structure and morphology of the synthesized powders were investigated by X-ray diffraction (XRD), Infrared spectroscopy, Impedance analyzer etc. The influence of lithium composition (x) on structural, electronic and optical properties of lithium cobaltite was studied. Temperature dependent electrical resistivity was measured using four-probe technique. While LixCoO2 with x = 0.9 is a semiconductor, the highly Li-deficient phase (0.75 ? x ? 0.5) exhibits metallic conductivity. The ionic conductivity of LixCoO2 (x = 0.5 – 1.15) was measured using impedance spectroscopy and maximum conductivity of Li0.5CoO2 was found to be 6.5×10-6 S/cm at 273 K. The properties that are important for applications, such as ionic conductivity, charge capacity, and optical absorption are observed to increase with Li deficiency. Keywords: Calcination; Characterization; Inorganic compounds; Solid-State reaction; X-ray diffraction. © 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v6i2.17900 J. Sci. Res. 6 (2), 217-231 (2014)  


Sign in / Sign up

Export Citation Format

Share Document