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Synthesis of ZrC Nanoparticles in the ZrO_2–Mg–C–Fe System Through Mechanically Activated Self-Propagating High-Temperature Synthesis

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Acta Metallurgica Sinica(English Letters) 2014年第6期27卷 1144-1151页

作者： Abdollah Hajalilou mansor hashim Halimah Mohamed kamari Kazem Javadi Samikannu Kanagesan Mohammad Parastegari Materials Synthesis and Characterization Laboratory Institute of Advanced Technology (ITMA) University Putra Malaysia Physics Department University Putra Malaysia Irankhodrow Industry Mechanical Testing Laboratory Materials Synthesis and Characterization Laboratory Isfahan University of Technology

ZrC nanoparticles in the matrix of Fe were produced by the mechanically activated self-propagating hightemperature method using ZrO2/C/Mg/Fe powder mixtures. The effects of milling time, Fe content, and combustion temperature as well as the formation route for synthesizing ZrC powder particles were studied. The samples were characterized by XRD, SEM, TEM, and DTA. The XRD results revealed that, after 18 h of mechanical activation, ZrO2/ZC/Mg/Fe reacted with the self-propagating combustion（SHS） mode at 870 °C producing the ZrC–Fe nanocomposite. It was also found that both mechanical activation and Fe content played key roles in the ZrC synthesis temperature. With a Fe content of（5–40） wt%, the SHS reaction proceeded favorably and both the ZrC formation temperature and the adiabatic temperature（Tad） decreased. The Mg O content was removed from the final products using a leaching test process by dissolving in hydrochloric and acetic acids.

关键词： Mechanical activation(MA) Combustion synthesis Fe–ZrC composite Leaching process

Morphology and dielectric properties of single sample Ni_(0.5)Zn_(0.5)Fe_(2)O_(4)nanoparticles prepared via mechanical alloying

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Journal of Advanced Ceramics 2014年第4期3卷 306-316页

作者： Rafidah HASSAN Jumiah HASSAN mansor hashim Suriati PAIMAN Raba′ah Syahidah AZIS Physics Department Faculty of ScienceUniversiti Putra Malaysia43400 UPM SerdangSelangorMalaysia Institute of Advanced Technology University Putra Malaysia43400 UPM SerdangSelangorMalaysia

Nickel-zinc ferrite nanoparticles are important soft magnetic materials for high and low frequency device application and good dielectric ***-zinc ferrite nanoparticles with composition Ni_(0.5)Zn_(0.5)Fe_(2)O_(4)were prepared using mechanical alloying to analyze the effect of sintering temperature on microstructure evolution of a single sample with dielectric *** single sample with nanosized pellet was sintered from 600℃to 1200℃and analyzed by X-ray diffraction(XRD)to investigate the phases of the powders and by field emission scanning electron microscopy(FESEM)for the morphology and microstructure *** properties such as dielectric constant(e″)and dielectric loss(e′)were studied as functions of frequency and temperature for Ni_(0.5)Zn_(0.5)Fe_(2)O_(4).The dielectric properties of the sample were measured using HP 4192A LF impedance analyzer in the low frequency range from 40 Hz to 1 MHz and at temperature ranging from 30℃to 250℃.The results showed that single phase Ni_(0.5)Zn_(0.5)Fe_(2)O_(4)cannot be formed by milling alone and therefore requires *** crystallization of the ferrite sample increased with increasing sintering temperature,while the porosity decreased and the density and average grain size *** of the microstructure resulted in three activation energies of grain growth,where above 850℃there was a rapid grain growth in the *** constant and loss factor decreased with the increase in *** optimum sintering temperature of Ni_(0.5)Zn_(0.5)Fe_(2)O_(4)was found to be 900℃which had high dielectric constant and low dielectric loss.

关键词： mechanical alloying sintering temperature dielectric properties

Dielectric Properties of Nickel-Zinc Ferrite at Low Frequencies

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材料科学与工程（中英文版） 2010年第6期4卷 9-12页

作者： Wong Swee Yin Jumiah Hassan mansor hashim Oepartment of Physics Faculty of Science Universiti Putra Malaysia UPM Serdang 43400 Selangor Malaysia

Effect of Sintering Temperature on Co0.5Zn0.5Fe2O4Nano-Particles Evolution and Particle Size Distribution

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Advances in Nanoparticles 2015年第2期4卷 37-44页

作者： Abubakar Yakubu Zulkifly Abbas mansor hashim Ahmad Fahad Department of Physics Faculty of Science Universiti Putra Malaysia Selangor Malaysia Institute of Advance Technology and Material Science (ITMA) Universiti Putra Malaysia Selangor Malaysia Institute of Mathematical Research (INSPEM) Universiti Putra Malaysia Selangor Malaysia

This study involves an investigation to ascertain the effect of sintering temperature on the particle size distribution of Co0.5 Zn0.5 Fe2O4 nano-particle. The effect of the sintering temperature towards diffusion of CoO and ZnO into the tetrahedral and octahedral sites was also reported. In this study, CoO, ZnO and Fe2O3 powders were mechanically alloyed to synthesize fine powders of Co0.5 Zn0.5 Fe2O4 nano-particles. The synthesized powder was then sintered at various temperatures which were employed to study the effect of sintering temperature on the materials. Further analysis was done using XRD to investigate the phases of the powder and the crystallite size using Scherrer equation, SEM and EDX for the morphology and elemental composition of samples. The XRD spectra indicated that Both ZnO and CoO powder reacted well during sintering, however, ZnO was first to diffuse into its crystallographic sites before CoO. While the particle size distribution increases as the sintering temperature increases. Amongst other findings, it was confirmed that sintering temperature affects the particle size distribution of samples and samples begin to agglomerate at temperature above 700°C.

关键词： Sintering Temperature Mechanical Alloy Agglomerate Nanoparticles

Effect of Milling Time on Co0.5Zn0.5Fe2O4Microstructure and Particles Size Evolution via the Mechanical Alloying Method

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Journal of Materials Science and Chemical Engineering 2014年第11期2卷 58-63页

作者： Abubakar Yakubu Zulkifly Abbas mansor hashim Ahmad Fahad Departament of Physics Universiti Putra Malaysia Serdang Malaysia Institute of Advance Material Science Universiti Putra Malaysia Serdang Malaysia Institute of Mathematical Research Universiti Putra Malaysia Serdang Malaysia

Nanocrystalline CoZn-ferrite was fabricated by a high-energy milling method by mixing Fe3O4+CoO+ZnO. The structural properties of the milled powder at different milling times were analysed so to ascertain the diffusion of CoO and ZnO into the tetrahedral and octahedral sites using mechanical alloying method. The effect of mechanical alloying towards particle size was also investigated. The XRD spectra indicated the precursors reacted during milling with the diffusion of ZnO and followed by CoO into their respective crystallographic sites. SEM micrographs showed the agglomeration of powders due to high energy milling and TEM images confirmed that the particles of the materials were of nanosize dimension. In addition, the results show that the grain possesses a single-phase CoZn-ferrite structure in a typical size of ~16–30 nm. The experiment reveals that nanosize CoZn-ferrite can be obtained after the powder is milled for about 8 hours at room temperature. The mechanism and efficiency of the synthesis of the technique are also discussed in this paper.

关键词： Mechanical Alloying CoZn-Ferrite Nanocrystalline XRD Profile

Microwave Sintering of Zn-Nb Doped Barium Hexaferrite Synthesized via Sol-Gel Method

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Materials Sciences and Applications 2014年第4期5卷 171-176页

作者： Samikannu Kanagesan mansor hashim Sinnappan Jesurani Thirunavukarasu Kalaivani Ismayadi Ismail Center for Material Science and Nano Devices Department of Physics SRM University Kattankulathur India Department of Physics Jeyaraj Annapackium College for Women Periyakulam India Materials Synthesis and Characterization Laboratory (MSCL) Institute of Advanced Technology (ITMA) Universiti Putra Malaysia Serdang Malaysia

A series of polycrystalline M-type hexagonal ferrites with the formula BaFe12-2xZnx NbxO19 (x = 0.2, 0.4, 0.6, 0.8 mol%) have been synthesized by the sol-gel method. The composition and microstructure govern the magnetic properties of ferrites. The XRD analysis shows the formation of pure magneto plumbite phase without any other impurity phases. The Zn-Nb substitutions in barium hexaferrite have been confirmed through magnetic measurements. The results show that the magnetic properties are closely related to the distributions of Zn-Nb ions on the five crystallographic sites. The saturation magnetization and coercivity increase with increasing Zn-Nb concentration.

关键词： Ceramics Magnetic Materials Surface Properties Magnetic Properties

Complex dielectric modulus and relaxation response at low microwave frequency region of dielectric ceramic Ba_(6-3x)Nd_(8+2x)Ti_(18)O_(54)

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Journal of Advanced Dielectrics 2014年第4期4卷 57-64页

作者： Chian Heng Lee Jumiah Hassan mansor hashim Raba'ah Syahidah Aziz Norlaily Mohd Saiden Department of Physics Universiti Putra Malaysia 43400 Serdang SelangorMalaysia Institute of Advanced Technology Universiti Putra Malaysia 43400 Serdang Selangor Malaysia

The desirable characteristics of Ba_(6-3x)Nd_(8+2x)Ti_(18)O_(54)include high dielectric constant,low loss tangent,and high quality factor developed a new field for electronic *** microwave dielectric properties of Ba_(6-3x)Nd_(8+2x)Ti_(18)O_(54),with x?0:15 ceramics at different sintering temperatures(600–1300C)were *** phenomenon of polarization produced by the applied electric field was *** dielectric properties with respect to frequency from 1MHz to 1.5 GHz were measured using Impedance Analyzer,and the results were compared and *** highest dielectric permittivity and lowest loss factor were defined among the *** complex dielectric modulus was evaluated from the measured parameters of dielectric measurement in the same frequency range,and used to differentiate the contribution of grain and grain boundary.

关键词： Ceramic sintering dielectric response electrochemical impedance spectroscopy

The Influence of Seasonal Changes and Headwaters on Physico-chemical Dynamics of Temengor Reservoir, Malaysia

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湿地科学 2011年第4期9卷 314-321页

作者： Zarul Hazrin hashim Asmah Patiroi Mashhor mansor Shahrul Anuar Md. Sah Donald C. Jackson School of Biological Sciences Universiti Sains Malaysia Department of Wildlife Fisheries and Aquaculture Mississippi State University

A study on physico-chemical dynamics of Temengor Reservoir was conducted to determine whether headwaters and seasonal changes play a major role in regulating physico-chemical dynamics of Temengor Reservoir. Temengor Reservoir receives water from its surrounding water catchments and headwaters. Then, the water flows into a series of hydroelectric dams, namely the Bersia, Kenering and Chenderoh dams. Generally, water quality in Temengor Reservoir can be classified as Class I. Physico-chemical trends showed that water quality in euphotic zone of Temengor Reservoir is stable and consistent. Two-way ANOVA analyses showed that seasonal variations only affected water temperature, Secchi disc's depth and nitrate-nitrogen. Based on Tukey's post-hoc test, all three headwaters in this study exert no influence to the reservoir's water quality. These insignificant differences were probably due to water temperature and the size of the headwaters and the reservoir itself. In situ parameters profiling showed that the epilimnion zone in Temengor Reservoir is from the surface to 6 m depth, the metalimnion zone is from 6 m to 12 m depth and the hypolimnion zone is from 12 m depth onwards to the bottom of the reservoir. Thus, continuous water profiling monitoring that covers high and low water levels need to be conducted to determine characteristics of the physico-chemical dynamics in the water column and also to analyse changes in reservoir layers. Through these studies, discontinuity trends in the Perak River could be determined and suggestions to the respective agencies could be made to conserve and to sustain downstream biodiversity.

关键词：湿地物理化学季节变化研究分析

The Recovery of Two Long-logged Headwaters in Temengor Reservoir,Perak,Malaysia

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湿地科学 2011年第2期9卷 140-150页

作者： Zarul Hazrin hashim Amir Shah Ruddin Md Shah Khoo Khay Huat Shahrul Anuar Md.Sah Mashhor mansor School of Biological Sciences Universiti Sains Malaysia11800 USM Pulau PinangMalaysia

A study on water quality of the two long-logged and abandoned headwaters in Temengor Reservoir was conducted to determine their natural *** this study,we used National Water Quality Standards for Malaysia prepared by Malaysian Department of Environment as an indicator for water quality *** parameters measured were dissolved oxygen（mg/L）,water temperature（℃）,pH,conductivity（mS/cm）,total dissolved solids（mg/ L）,water velocity（m/s）,ortho-phosphate（PO4-P）,nitrite-nitrogen（NO2-N）,nitrate-nitrogen（NO3,-N）and alkalinity. In general,water quality in Sungai Enam and Sungai Telang were in ClassⅠ,indicating water quality in both streams have *** on the t-test,Sungai Enam and Sungai Telang differed significantly in all parameters except for dissolved oxygen,NO2-N and *** spatial analyses（upper,middle and lower reaches comparisons）, the two-way ANOVA analysis shows that there were significant differences in all studied parameters between the two rivers except for dissolved oxygen,total dissolved solids,NO2-N and *** flow,hydrologic pathways,geomorphology,physical and environmental characteristics are essential elements in understanding the dynamics of water systems in Sungai Enam and Sungai *** to the recovery,these two headwaters are thus suitable for fish conservation and restoration sites.

关键词： water quality Temengor Reservoir hydrology nutrient headwaters