scholarly journals d0-Ferromagnetism in SHS Titanium Nitride Treated by Ball Milling

2019 ◽  
Vol 21 (4) ◽  
pp. 347
Author(s):  
M.L. Busurina ◽  
O.V. Belousova ◽  
I.D. Kovalev ◽  
A.E. Sytschev
Keyword(s):  
Titanium Nitride ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mechanical Treatment ◽  
Milling Time ◽  
Area Measurement ◽  
Specific Magnetization ◽  
Nitride Powder ◽  
Milled Powders

In this work, the influence of mechanical treatment (mechanical milling) of the TiN titanium nitride powder produced by self-propagating high-temperature synthesis on the magnetic properties of the milled powders is investigated. The effect of d0-magnetization was observed. The TiN powders were characterized by scanning electron microscopy, X-ray diffraction, vibrating-sample magnetometry, specific surface area measurement, and chemical analysis. The results show that the mechanical treatment of the TiN titanium nitride powder influences the magnetization in a nonmonotonic manner. The conditions of mechanical treatment corresponding to the best value of specific magnetization of milled powders were established. The specific magnetization depended on three measured parameters: specific surface area, coherent scattering region, and average particle size. It was shown that unit cell parameters of milled TiN titanium nitride powders have not been changed with the increasing of duration milling time. The calculated values of CSR of mechanically treated powders decreased with the increasing of duration of milling time. The values of macrostrains were negative. Mechanical treatment of the TiN titanium nitride powders has led to a change in the nitrogen content from 21.4 to 20.0 wt.%. Stoichiometry of the TiN titanium nitride varied from TiN0.903-TiN0.886; therefore, the observed d0-magnetization effect is associated with a defective surface structure of mechanically treated powders.

Changes in Particle Size and Crystallinity in Ground Nickel Powder

2008 ◽  
Vol 587-588 ◽  
pp. 468-472
Author(s):  
J.M. González ◽  
José A. Rodríguez ◽  
Enrique J. Herrera
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Crystallite Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Nickel Powder ◽  
Milling Time ◽  
High Energy ◽  
Published Data ◽  
Average Particle

Nickel powder was dry-milled using a high-energy disc-oscillating mill. The average particle size increases and the specific surface area diminishes with milling time. Crystallite size decreases and microstrains increase, under the same conditions, as shown by X-ray analysis. At 120 min milling time, the crystallite size has a value of 17 nm, i.e., a nanostructured powder, with a perturbed lattice, is obtained. The above results have been compared with published data about the effects of milling on a ceramic powder. There is, in both cases, a general agreement concerning the changes produced in crystallite size. Nevertheless, opposite results are reached regarding particle size and specific surface area.

Nd-Doped Barium Cerate Nano-Sized Catalyst Converts CH4 into CO2 at Lower Temperature Compared to Noble Metal-Based Pd/Al2O3 Catalyst

2021 ◽  
Vol 10 (3) ◽  
pp. 01-08
Author(s):  
Khalid Ouzaouit ◽  
Abdelhay Aboulaich
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Catalytic Properties ◽  
Area Measurement ◽  
Barium Cerate ◽  
In Situ Ftir Spectroscopy ◽  
Lower Temperature ◽  
Doped Barium Cerate ◽  
Al2o3 Catalyst

The present paper describes the synthesis and first application of Nd-doped BaCeO3 nanoparticles as catalyst for the catalytic oxidation of methane (CH4) into CO2. Nd-doped barium cerate BaCeO3 nanoparticles, with the formula BaNdxCe(1-x)O3, have been prepared using a simple sol gel method starting from acetate precursors. The as-prepared nanoparticles have been fully characterized by XRD, TEM, HRTEM and specific surface area measurement. Results confirmed the formation of highly crystallized nano-sized particles with small crystallite size. In-situ FTIR spectroscopy was used to study the catalytic conversion of methane (CH4) into CO2 in the presence of the as-prepared Nd-doped BaCeO3 nanocatalyst. The catalytic properties of such nanocatalysts have been discussed and correlated to Nd-doping rate, crystallite diameter, and specific surface area of the materials. Excellent catalytic properties have been obtained with BaNd0.05Ce0.95O3, such as, superior conversion efficiency, longer catalysis lifetime and lower activation temperature compared to un-doped BaCeO3 catalyst. Interestingly, it was found that BaNd0.05Ce0.95O3 nanocatalyst successfully converts the totality of CH4 present in a mixture of CH4-Air into CO2 at much lower temperature compared to the conventional Pd/Al2O3 catalyst.

scholarly journals Study of the transport properties of composite solid electrolytes LiClO4-MgAl2O4

2021 ◽  
Vol 340 ◽  
pp. 01038
Author(s):  
Dmitriy Alekseev ◽  
Vyacheslav Khusnutdinov ◽  
Yulia Mateyshina
Keyword(s):  
Specific Surface ◽  
Transport Properties ◽  
Surface Area ◽  
Specific Surface Area ◽  
Solid Electrolytes ◽  
Mechanical Treatment ◽  
Magnesium Aluminum Spinel ◽  
Composite Solid Electrolytes ◽  
Composite Solid ◽  
Nanocrystalline Sample

Magnesium-aluminum spinel MgAl2O4 was synthesized by mechanical treatment of a mixture of hydroxides followed by treatment of the solution at 80 ° C and sintering at 850° C. The obtained nanocrystalline sample with a specific surface area of 100 m2/g were used for the preparation of composite solid electrolytes (1-x) LiClO4-xMgAl2O4. It was shown that conductivity increases with the spinel concentration and goes through a maximum of 1.35·10-2 S/cm at 150 °C for composite 0.3LiClO4-0.7MgAl2O4.

scholarly journals Mechanical Activation of Granulated Copper Slag and Its Influence on Hydration Heat and Compressive Strength of Blended Cement

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 772 ◽  
Author(s):  
Yan Feng ◽  
Jakob Kero ◽  
Qixing Yang ◽  
Qiusong Chen ◽  
Fredrik Engström ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Specific Surface ◽  
Mechanical Activation ◽  
Surface Area ◽  
Specific Surface Area ◽  
Milling Time ◽  
Copper Slag ◽  
Pozzolanic Activity ◽  
Hydration Heat ◽  
Strength Development

Mechanical activation of granulated copper slag (GCS) is carried out in the present study for the purposes of enhancing pozzolanic activity for the GCS. A vibration mill mills the GCS for 1, 2, and 3 h to produce samples with specific surface area of 0.67, 1.03 and 1.37 m2/g, respectively. The samples are used to replace 30% cement (PC) to get 3 PC-GCS binders. The hydration heat and compressive strength are measured for the binders and derivative thermogravimetric /thermogravimetric analysis (DTG/TGA), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) are used to characterize the paste samples. It is shown that cumulative heat and compressive strength at different ages of hydration and curing, respectively, are higher for the binders blending the GCS milled for a longer time. The compressive strength after 90 d of curing for the binder with the longest milling time reaches 35.7 MPa, which is higher than the strength of other binders and close to the strength value of 39.3 MPa obtained by the PC pastes. The percentage of fixed lime by the binder pastes at 28 days is correlated with the degree of pozzolanic reaction and strength development. The percentage is higher for the binder blending the GCS with longer milling time and higher specific surface area. The pastes with binders blending the GCS of specific surface area of 0.67 and 1.37 m2/g fix lime of 15.20 and 21.15%, respectively. These results together with results from X-ray diffraction (XRD), FTIR, and SEM investigations demonstrate that the mechanical activation via vibratory milling is an effective method to enhance the pozzolanic activity and the extent for cement substitution by the GCS as a suitable supplementary cementitious material (SCM).

The Research on Lining Board Preparation of Mesoporous Zeolites

2012 ◽  
Vol 454 ◽  
pp. 130-135
Author(s):  
Zhi Jun Ma ◽  
Yi Min Zhu ◽  
Yue Xin Han ◽  
Xin Fang
Keyword(s):  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Crystallization Temperature ◽  
Area Measurement ◽  
Crystallization Time ◽  
Mesoporous Zeolite ◽  
Crystallization Pressure ◽  
Pressure Crystallization

In this paper, uses composite template, through the hydrothermal synthesis of mesoporous zeolite, and N2 adsorption specific surface area measurement instrument, scanning electron microscopy ( SEM ) on mesoporous zeolite pore size, morphology characterization, the crystallization pressure, crystallization temperature, crystallization time on mesoporous zeolite pore size, specific surface area, morphology of the impact. The results show that : the selection of P123 composite beer yeast as template agent, under the condition of high pressure crystallization ( control crystallization pressure 2.3MPa ), crystallization temperature of 110°C, the crystallization time is 72h, prepared by 10nm, specific surface area pore size of 400m2 / g mesoporous zeolite.

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