Particularities of Structure and Stability of Cationic-Ordered Layered Titanates

2011 ◽  
Vol 170 ◽  
pp. 190-193 ◽  
Author(s):  
Irina Zvereva ◽  
Anna Sankovich ◽  
Alexander Missyul

Thermal stability of the layered titanates NdMTiO4 and Nd2M2Ti3O10 (M=Na, K) featured with 1 or 3 perovskite layers has been investigated in thermal annealing at 780 – 1400°С. Their structure variations are monitored using thermal analysis (TGA, DTA), X-ray powder diffraction, and scanning electron microscopy. Judging from the decomposition sequence and the stable temperature range for individual phase, the structure of Nd2M2Ti3O10 with three perovskite layers is identified most stable among these layer titanates. As a whole, the K-containing phases are less stable than the Na-containing ones.

2018 ◽  
Vol 930 ◽  
pp. 224-229
Author(s):  
Marcos Antônio Guerra ◽  
Jeferson Prado Swerts ◽  
Mei Abe Funcia ◽  
Neide Aparecida Mariano ◽  
Maria Gabriela Nogueira Campos

Polyethylene terephthalate (PET) fiber is a very versatile fiber that can be produced with different properties, such as antimicrobial activity. This study aims to synthesize antimicrobial PET filaments incorporated with silver nanoparticles immobilized in silica (NPAg-Si) by bulk additive method. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) characterized the obtained filaments at concentrations (w/w) of 0.008%, 0.016%, 0.032%, 0.047% and 0.063% NPAg-Si, in order to identify the nanoparticles and analyze their dispersion in the polymeric matrix. Moreover, thermogravimetric analysis (TGA) was carry out to confirm the presence and concentration of the silver nanoparticles in the filaments as well as the thermal stability of the nanocomposites. The bulk addition method was efficient to produce PET-Silver filaments with silver nanoparticles homogeneously dispersed in the PET matrix.


2013 ◽  
Vol 334-335 ◽  
pp. 60-64 ◽  
Author(s):  
Mohammad Reza Loghman-Estark ◽  
Reza Shoja Razavi ◽  
Hossein Edris

Scandia, yttria doped zirconia ((ZrO2)0.96(REO1.5)0.04(RE=Sc3+, Y3+)) nanoparticles were prepared by the modified sol-gel method. The microstructure of the products was characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. Thermal stabillity of SYSZ nanocrystals were also investigated. The SYSZ nanocrystals synthesized with EGM:Zr+4mole ratio 4:1, calcined at 700°C, have average diameter of ~20 nm.


1999 ◽  
Vol 564 ◽  
Author(s):  
D. Mangelinck ◽  
J. Y. Dai ◽  
S. K. Lahiri ◽  
C. S. Ho ◽  
T. Osipowicz

AbstractThe effect of a small amount of Pt (5 at.%) on the thermal stability of NiSi film on (100)Si and (111 )Si has been investigated. Rutherford back scattering, Scanning Electron Microscopy, and X-ray diffraction have been used to study the formation, microstructure and orientation of the silicide. The addition of platinum results in increasing the disilicide nucleation temperature to 900°C and thus leads to a better stability of NiSi at high IC processing temperatures. The presence of Pt also induced a texture of the NiSi film both on (11 1)Si and (100)Si. The increase in thermal stability is explained in terms of nucleation controlled reaction concept and should open new possibilities for the use of NiSi in self aligned silicidation. The redistribution of Pt in the silicide is examined and explained in terms of kinetics and thermodynamics considerations. The addition of Pt also increases the temperature of agglomeration of NiSi.


2013 ◽  
Vol 815 ◽  
pp. 126-129
Author(s):  
Wei He ◽  
Yong Zhi Zhang ◽  
Yun Hong Zhao ◽  
Ling Min Zeng

The rare earth-cobalt compounds with CaCu5-type structure were discovered to have outstanding permanent magnetic properties. The thermal stability of Y1-xErxCo5(x = 0, 0.12, 0.24) was investigated by X-ray powder diffraction, differential thermal analysis and scanning electron microscopy with energy dispersive analysis. The influence of Er for Y on the decomposition of Y1-xErxCo5was discussed. The substitution of Er for Y in the compound YCo5obviously enhanced the decomposition temperature and accelerated the decomposition reaction of the compounds Y1-xErxCo5into (Y1-xErx)2Co17and (Y1-xErx)2Co7.


2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan  (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan  (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik  menggunakan analisis varian satu arah  SPSS 17.


2003 ◽  
Vol 17 (04n06) ◽  
pp. 899-904 ◽  
Author(s):  
A. VECCHIONE ◽  
M. GOMBOS ◽  
C. TEDESCO ◽  
A. IMMIRZI ◽  
L. MARCHESE ◽  
...  

NdSr 2 RuCu 2 O x material has been prepared as polycrystalline powder by solid state reaction. The compound has been investigated by synchrotron x-ray powder diffraction and scanning electron microscopy. The experimental results show that the average crystal structure is a disordered cubic perovskite with Nd and Sr cations occupying the same site and the same substitution is found for Cu and Ru atoms. A comparison between the crystal structure and morphology of this compound and the superconducting tetragonal GdSr 2 RuCu 2 O 8 is also discussed.


2012 ◽  
Vol 174-177 ◽  
pp. 592-595
Author(s):  
Lin Lin Yang ◽  
Yong Gang Wang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang

The organization of nanostructures across extended length scales is a key challenge in the design of integrated materials with advanced functions. PbZr0.52Ti0.48O3multilayer disks which were constructed by oriented rectangle nanoparticles were easily prepared by a simple surfactant-free hydrothermal process. The as-prepared powders were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that the as-prepared PZT disks were constructed by self-assembly of rectangle nanoparticles by a perfect manner. The formation mechanism of the products was discussed.


2020 ◽  
Vol 985 ◽  
pp. 86-90
Author(s):  
Andi Muhammad Anshar ◽  
Sengo Kobayashi ◽  
Satoshi Okano

The surface wettability of biomaterials influences on osteoblast behavior and bone formation. In this research, the variation of wettability of nacre by heat treatments was examined. Plates of the nacre were fabricated from shells of the Akoya pearl oyster. The specimens were heated at 100, 200, 300, 400, 500, and 600 °C. Characterizations of the specimens during and after heat treatments were carried out using scanning electron microscopy, X-ray diffractometry, and thermogravimetry-differential thermal analysis. The water contact angle (WCA) of the specimen was measured to evaluate wettability. The color of nacre changed from iridescent color to brownish weak-iridescence by the heating at and over 300 °C. The nacre heated at and over 300 °C became brittle because organic substances in nacre, which acts as the glue between the aragonite platelets were evaporated by the heating. The WCA of the specimen was decreased with increasing heating temperature, which should be related to the decrease in the number of organic substances in nacre by the heating.


2013 ◽  
Vol 467 ◽  
pp. 3-7
Author(s):  
Hui Fen Yang ◽  
Lin Fei Lu ◽  
Bei Ping Jiang ◽  
Jin Long Zhang

Based on analyzing of chemical composition, mineral composition and thermal stability of red mud, preparation of ceramisite, using anthracite added as foaming agent, was investigated. Internal structure was observed by scanning electron microscopy (SEM). The results showed the bulk density of ceramisite was obviously reduced by anthracite added. The ceramisite with bulk density of 1.30g/cm3, water absorption rate£ ̈WAR£©of 2.98% and cylinder compressive strength £ ̈CCS£©of 9.48 MPa was obtained when weight ratio of red mud/waste glass/bentonites/anthracite was at 73:15:11:1. Majority of porosity in ceramisite was closed based on SEM. The porosity of ceramisite was much higher when anthracite was added as foaming agent than only calcite in red mud was used as foaming agent. The bulk density of the former was lower than that of the latter.


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