scholarly journals Study of the Structural, Morphological and Electrical Properties of WO3 Nanopowders which Use as Gas Sensors

2015 ◽  
Vol 60 ◽  
pp. 107-112
Author(s):  
Malek Ali ◽  
Mayada Hbous
Keyword(s):  
Crystal Structure ◽  
Electrical Properties ◽  
Surface Morphology ◽  
Gas Sensors ◽  
High Energy ◽  
X Ray Diffraction ◽  
Mill Time ◽  
Methanol Vapor ◽  
Structure Surface ◽  
Energy Ball

nanopowders of tungsten oxide (WO3) have been prepared by high energy ball-milling for various spans of mill time (1-18 h). The crystal structure, surface morphology of the prepared WO3 nanopowder were characterized by X-ray diffraction and scanning electron microscope. Thick films of WO3 nanopowders were prepared by printing painting chemical method to use them as gas sensors for methanol vapor at different operating temperatures, Their I-V characteristics were studied by using devices KEITHLEY 237. The effect of the milling time on the crystal structure, surface morphology, and electrical properties are reported.

scholarly journals Crystal Structure Evolution, Microstructure Formation, and Properties of Mechanically Alloyed Ultrafine-Grained Ti-Zr-Nb Alloys at 36≤Ti≤70 (at. %)

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 587 ◽  
Author(s):  
Marczewski ◽  
Miklaszewski ◽  
Maeder ◽  
Jurczyk
Keyword(s):  
Crystal Structure ◽  
Mechanical Alloying ◽  
Pure Titanium ◽  
Young Modulus ◽  
High Energy ◽  
Structure Evolution ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Ultrafine Grained ◽  
Energy Ball

Titanium β-type alloys are preferred biomaterials for hard tissue replacements due to the low Young modulus and limitation of harmful aluminum and vanadium present in the commercially available Ti6Al4V alloy. The aim of this study was to develop a new ternary Ti-Zr-Nb system at 36≤Ti≤70 (at. %). The technical viability of preparing Ti-Zr-Nb alloys by high-energy ball-milling in a SPEX 8000 mill has been studied. These materials were prepared by the combination of mechanical alloying and powder metallurgy approach with cold powder compaction and sintering. Changes in the crystal structure as a function of the milling time were investigated using X-ray diffraction. Our study has shown that mechanical alloying supported by cold pressing and sintering at the temperature below α→β transus (600°C) can be applied to synthesize single-phase, ultrafine-grained, bulk Ti(β)-type Ti30Zr17Nb, Ti23Zr25Nb, Ti30Zr26Nb, Ti22Zr34Nb, and Ti30Zr34Nb alloys. Alloys with lower content of Zr and Nb need higher sintering temperatures to have them fully recrystallized. The properties of developed materials are also engrossing in terms of their biomedical use with Young modulus significantly lower than that of pure titanium.

scholarly journals The influence of compaction pressure on the density and electrical properties of cordierite-based ceramics

2015 ◽  
Vol 47 (1) ◽  
pp. 15-22 ◽  
Author(s):  
N. Obradovic ◽  
N. Djordjevic ◽  
A. Peles ◽  
S. Filipovic ◽  
M. Mitric ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Ball Mill ◽  
Compaction Pressure ◽  
High Energy ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Air Atmosphere ◽  
High Energy Ball Mill ◽  
Energy Ball

Due to its characteristics, cordierite, 2MgO?2Al2O3?5SiO2, is a high-temperature ceramic material of a great scientific interest. Mechanical activation of the starting mixtures containing 5.00 mass% TiO2 was performed in a high-energy ball mill for 10 minutes. The compaction pressure varied from 0.5 to 6tcm-2 (49-588 MPa). The sintering process was performed at 1350?C for four hours in the air atmosphere. The phase composition of the activated and sintered samples was analyzed using X-ray diffraction. Scanning electron microscopy was used to analyze the microstructure of both compacted and sintered samples. The authors have investigated the influence of compaction pressure on the sintered samples and their electrical properties.

scholarly journals Effects of Recycled Fe2O3 Nanofiller on the Structural, Thermal, Mechanical, Dielectric, and Magnetic Properties of PTFE Matrix

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2332
Author(s):  
Ahmad Mamoun Khamis ◽  
Zulkifly Abbas ◽  
Raba’ah Syahidah Azis ◽  
Ebenezer Ekow Mensah ◽  
Ibrahim Abubakar Alhaji
Keyword(s):  
Electron Microscopy ◽  
High Energy ◽  
Filler Loading ◽  
Complex Permeability ◽  
X Ray Diffraction ◽  
Thermal Expansion Coefficients ◽  
Transmission Electron ◽  
Energy Ball ◽  
Hematite Fe2o3 ◽  
Ptfe Composites

The purpose of this study was to improve the dielectric, magnetic, and thermal properties of polytetrafluoroethylene (PTFE) composites using recycled Fe2O3 (rFe2O3) nanofiller. Hematite (Fe2O3) was recycled from mill scale waste and the particle size was reduced to 11.3 nm after 6 h of high-energy ball milling. Different compositions (5–25 wt %) of rFe2O3 nanoparticles were incorporated as a filler in the PTFE matrix through a hydraulic pressing and sintering method in order to fabricate rFe2O3–PTFE nanocomposites. The microstructure properties of rFe2O3 nanoparticles and the nanocomposites were characterized through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and high-resolution transmission electron microscopy (HRTEM). The thermal expansion coefficients (CTEs) of the PTFE matrix and nanocomposites were determined using a dilatometer apparatus. The complex permittivity and permeability were measured using rectangular waveguide connected to vector network analyzer (VNA) in the frequency range 8.2–12.4 GHz. The CTE of PTFE matrix decreased from 65.28×10−6/°C to 39.84×10−6/°C when the filler loading increased to 25 wt %. The real (ε′) and imaginary (ε″) parts of permittivity increased with the rFe2O3 loading and reached maximum values of 3.1 and 0.23 at 8 GHz when the filler loading was increased from 5 to 25 wt %. A maximum complex permeability of 1.1−j0.07 was also achieved by 25 wt % nanocomposite at 10 GHz.

scholarly journals Magnetic properties and crystal structure of elemental cobalt powder modified by high-energy ball milling

2019 ◽  
Vol 8 (5) ◽  
pp. 4995-5003 ◽  
Author(s):  
J.A. Betancourt-Cantera ◽  
F. Sánchez-De Jesús ◽  
A.M. Bolarín-Miró ◽  
G. Torres-Villaseñor ◽  
L.G. Betancourt-Cantera
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Cobalt Powder ◽  
Energy Ball

Nanocrystalline Nd2Fe17synthesized by high-energy ball milling: crystal structure, microstructure and magnetic properties

2010 ◽  
Vol 22 (21) ◽  
pp. 216005 ◽  
Author(s):  
Pablo Álvarez ◽  
Pedro Gorria ◽  
Victorino Franco ◽  
Jorge Sánchez Marcos ◽  
María J Pérez ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Energy Ball ◽  
Microstructure And Magnetic Properties

Structural and electrochemical properties of Ti–Ru–Fe–O alloys prepared by high energy ball-milling

1998 ◽  
Vol 13 (5) ◽  
pp. 1171-1176 ◽  
Author(s):  
S-H. Yip ◽  
D. Guay ◽  
S. Jin ◽  
E. Ghali ◽  
A. Van Neste ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
High Energy ◽  
X Ray Diffraction ◽  
Long Term Stability ◽  
Ternary Metal ◽  
Oxide Phases ◽  
Energy Ball ◽  
Diffraction Patterns ◽  
B2 Structure

The structural and electrochemical properties of the Ti–Ru–Fe–O system have been studied over the whole ternary metal compositional range, keeping constant the oxygen content at 30 at.%. The phase diagram was explored systematically by varying the composition of the material along one of the following axes: (i) constant Ru content of 16 at. %; (ii) constant Ti/Ru ratio of 2; (iii) constant Ti/Fe ratio of 1.6. For O/Ti ratios equal or below unity, the most prominent peaks observed in the x-ray diffraction patterns belong to a B2 structure. For O/Ti ratio larger than unity, stable titanium oxide phases are formed, which coexist with a cubic Fe-like or hcp-Ru like phases depending on the Fe/Ru ratio. Powder compositions with stoichiometry close to Ti2RuFeO2 are of interest due to good electrocatalytic properties, long-term stability, and low Ru content.

scholarly journals Influence of prolonged sintering time on density and electrical properties of isothermally sintered cordierite-based ceramics

2013 ◽  
Vol 45 (2) ◽  
pp. 157-164 ◽  
Author(s):  
A. Peles ◽  
N. Djordjevic ◽  
N. Obradovic ◽  
N. Tadic ◽  
V.B. Pavlovic
Keyword(s):  
Electrical Properties ◽  
Mechanical Activation ◽  
Compaction Pressure ◽  
High Energy ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Air Atmosphere ◽  
Atomic Force ◽  
Sintering Time ◽  
High Energy Ball Mill

Mechanical activation is a commonly used and relatively fast and inexpensive procedure for sample preparation before the sintering process. Cordierite, a stoichiometric mixture of three different oxides (2MgO?2Al2O3?5SiO2) is a very attractive, widely used high-temperature ceramic material. The mechanical activation of the starting mixtures with 5.00 mass% TiO2 was performed in a high energy ball mill during 10-80 min. The applied compaction pressure before the sintering process was 2t/cm2, based on our recent investigation. The sintering process was performed at 1350oC for 2h and 4h in air atmosphere. X-ray diffraction was used to analyze the phase composition of non-activated and 80 min activated samples, sintered for 2 and 4h, respectively. Scanning electron microscopy was performed to analyze the microstructure of both compacted and sintered samples. Atomic force microscope was used to investigate the surface of the sintered samples. This paper investigates the influence of prolonged sintering time on the densities of the sintered samples, along with electrical properties.

High-performance electrical properties of La-based perovskite ceramics for the functional phase of thick film resistors

2020 ◽  
Author(s):  
Yongcheng Lu ◽  
Yuanxun Li ◽  
Daming Chen ◽  
Rui Peng ◽  
Qinghui Yang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electrical Properties ◽  
Thick Film ◽  
High Performance ◽  
Composite Ceramics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Alternative Material ◽  
Perovskite Ceramics ◽  
Scanning Electron

Abstract In order to explore an economical functional phase alternative material for thick film resistors, the crystal structure, microstructure, and electrical properties of (1-x)LSCN + xLCNZ (x = 0.0–1.0) composite ceramics were studied through solid-state reaction experiments. The composite ceramics were characterized by x–ray diffraction, scanning electron microscopy, energy dispersive x–ray spectroscopy, and DC four–probe method. Results suggested that the main phases of LSCN and LCNZ were formed, along with a small part of impurity phases. The addition of LCNZ to LSCN decreased the electrical conductivity and changed the TCR from positive to negative. Zero TCR could be achieved around 0.6 < x < 0.8 and relatively low absolute TCR values could be obtained for the samples of 0.4 ≤ x ≤ 0.8. The ceramic of 0.6LSCN + 0.4LCNZ showed the optimal performances of conductivity = 1923 S/cm, TCR = 379.54 ppm/℃, and relative density = 95.05%.

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