Pub Date : 2013-09-06DOI: 10.4236/WJNSE.2013.33011
A. Boochani, S. Solymani, S. Rezaee, N. B. Nezafat, S. Tadayon, Amin Aminian
In this study, density functional theory in improved flat waves’ framework has been used. First of all, characterization, elastic and half-metallic properties of the CrSb-ZB compound at (GGA & LDA) and GGA + U approximation are calculated. The elastic calculations indicate that the CrSb-ZB is a ductile material. However, the calculation of Deby temperature indicates that the CrSb-ZB is meta-stable. The half-metallicity character is also preserved at CrSb/InP (001) interface by GGA + U. The conduction band minimum (CBM) of CrSb in the minority spin case lies about 1.26 eV above that of GaSb, suggesting that the major spin can be injected into GaSb without being flipped to the conduction bands of the minor spin.
{"title":"Physical Properties of CrSb/InP(001): Effect of Interface in Half-Metallic","authors":"A. Boochani, S. Solymani, S. Rezaee, N. B. Nezafat, S. Tadayon, Amin Aminian","doi":"10.4236/WJNSE.2013.33011","DOIUrl":"https://doi.org/10.4236/WJNSE.2013.33011","url":null,"abstract":"In this study, density functional theory in improved flat waves’ framework has been used. First of all, characterization, elastic and half-metallic properties of the CrSb-ZB compound at (GGA & LDA) and GGA + U approximation are calculated. The elastic calculations indicate that the CrSb-ZB is a ductile material. However, the calculation of Deby temperature indicates that the CrSb-ZB is meta-stable. The half-metallicity character is also preserved at CrSb/InP (001) interface by GGA + U. The conduction band minimum (CBM) of CrSb in the minority spin case lies about 1.26 eV above that of GaSb, suggesting that the major spin can be injected into GaSb without being flipped to the conduction bands of the minor spin.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70877155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-09-06DOI: 10.4236/WJNSE.2013.33012
M. Karimipour
TiO2 nano particles were synthesized in Rutile and Anatase phases by sol-gel method using two kind of complex agents, acidic (Citric Acid) and organic complex agent (acetyl acetone) at 400°C, 500°C, 650°C sintering temperatures. The structural analysis by XRD diffraction confirmed phase formation of titanium oxide. Particles sizes were determined by using Scherrer formula. TEM was employed to confirm nano particles formation. The size of nano particles as well as Phase formation can be controlled by the type of complex agent and sintering temperature. Acetyl Acetone causes a more crystalline structure and more uniformity of size distribution in 400°C sintering temperatures. Moreover, it results in obtaining single phase TiO2 nanoparticles at 400°C and 650°C sintering temperature. On the other hand, at high sintering temperature, the particles obtained from polymeric agent tend to agglomerate larger in size than the acidic product.
{"title":"Comparison of Acidic and Polymeric Agents in Synthesis of TiO 2 Nanoparticles via a Modified Sol-Gel Method","authors":"M. Karimipour","doi":"10.4236/WJNSE.2013.33012","DOIUrl":"https://doi.org/10.4236/WJNSE.2013.33012","url":null,"abstract":"TiO2 nano particles were synthesized in Rutile and Anatase phases by sol-gel method using two kind of complex agents, acidic (Citric Acid) and organic complex agent (acetyl acetone) at 400°C, 500°C, 650°C sintering temperatures. The structural analysis by XRD diffraction confirmed phase formation of titanium oxide. Particles sizes were determined by using Scherrer formula. TEM was employed to confirm nano particles formation. The size of nano particles as well as Phase formation can be controlled by the type of complex agent and sintering temperature. Acetyl Acetone causes a more crystalline structure and more uniformity of size distribution in 400°C sintering temperatures. Moreover, it results in obtaining single phase TiO2 nanoparticles at 400°C and 650°C sintering temperature. On the other hand, at high sintering temperature, the particles obtained from polymeric agent tend to agglomerate larger in size than the acidic product.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70877249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-09-06DOI: 10.4236/WJNSE.2013.33008
J. Nasser, A. Jesil, T. Mohiuddin, Majid Al Ruqeshi, G. Devi, Shahjahan Mohataram
In this work, a drilling fluid recipe has been developed by using nanoparticles, to increase the efficiency of drilling operations for maximum accessibility to new & matured oil reserves and suited to various drilling conditions. The solution to severe drilling problems like pipe sticking, lost circulation, formation damage, erosion of borehole, thermal instability of drilling fluids and insufficient gel properties of the drilling fluids, lies in controlling and optimizing the rheology of the drilling fluid. The inefficiency of the drilling fluid in performing certain functions is mainly due to a lack in a particular rheological property. The performance of the clay composites water-based bentonite drilling mud in terms of its rheological behavior in drilling systems was investigated at various pressures and temperatures. It was found that temperature had a detrimental effect on the rheological properties. The behavior was investigated using synthesized nano bentonite water based drilling fluid. The fluid retained all the desired rheological properties at elevated temperatures and pressures, thus enhanced the possibility of its application in deep wells, where elevated temperatures and pressures were quite common.
{"title":"Experimental Investigation of Drilling Fluid Performance as Nanoparticles","authors":"J. Nasser, A. Jesil, T. Mohiuddin, Majid Al Ruqeshi, G. Devi, Shahjahan Mohataram","doi":"10.4236/WJNSE.2013.33008","DOIUrl":"https://doi.org/10.4236/WJNSE.2013.33008","url":null,"abstract":"In this work, a drilling fluid recipe has been developed by using nanoparticles, to increase the efficiency of drilling operations for maximum accessibility to new & matured oil reserves and suited to various drilling conditions. The solution to severe drilling problems like pipe sticking, lost circulation, formation damage, erosion of borehole, thermal instability of drilling fluids and insufficient gel properties of the drilling fluids, lies in controlling and optimizing the rheology of the drilling fluid. The inefficiency of the drilling fluid in performing certain functions is mainly due to a lack in a particular rheological property. The performance of the clay composites water-based bentonite drilling mud in terms of its rheological behavior in drilling systems was investigated at various pressures and temperatures. It was found that temperature had a detrimental effect on the rheological properties. The behavior was investigated using synthesized nano bentonite water based drilling fluid. The fluid retained all the desired rheological properties at elevated temperatures and pressures, thus enhanced the possibility of its application in deep wells, where elevated temperatures and pressures were quite common.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70877405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-09-06DOI: 10.4236/WJNSE.2013.33009
T. Ahmad, W. Khan
The size evolution of gold nanoparticles synthesized using tannic acid with initial gold chloride concentrations ranging from 0.2 - 2 mM at various tannic acid to chloroauric acid molar ratios (ranging from 2:1 to 12:1) has been analysed. Dynamic light scattering spectroscopic and tramission electron microscopic analyses were performed to assess the size of formed gold nanoparticles. Two different patterns of nanoparticle size evolution were obtained; the size evolution trend below 1 mM chloroauric acid concentration was found to be different from the one obtained at gold chloride concentrations higher than or equal to 1 mM. In case of sizes obtained for less than 1 mM gold chloride concentration, a general decrease in particle size was observed with increase in gold salt concentration. On the contrary, for the particles synthesised using chloroauric acid concentrations higher than or equal to 1 mM, with increase in gold salt concentration, a general increase in nanoparticle diameter was seen. For the molarities 0.2 and 0.5 mM, with increase in tannic acid/ chloroauric acid ratios, first the size decreases and then increases and finally reaches saturation. Particles formed at molarities greater than equal to 1 mM do not exhibit plateaux in their size rather initially decrease and then increase in response to increasing tannic acid/chloroauric acid ratios except for 2 mM concentration at which a small saturation is observed. The findings enumerate that higher gold chloride concentrations leave a significant impact on the sizes of gold nanaparticles obtained using tannic acid as a reducing agent of chloroauric acid solution.
{"title":"Size Variation of Gold Nanoparticles Synthesized Using Tannic Acid in Response to Higher Chloroauric Acid Concentrations","authors":"T. Ahmad, W. Khan","doi":"10.4236/WJNSE.2013.33009","DOIUrl":"https://doi.org/10.4236/WJNSE.2013.33009","url":null,"abstract":"The size evolution of gold nanoparticles synthesized using tannic acid with initial gold chloride concentrations ranging from 0.2 - 2 mM at various tannic acid to chloroauric acid molar ratios (ranging from 2:1 to 12:1) has been analysed. Dynamic light scattering spectroscopic and tramission electron microscopic analyses were performed to assess the size of formed gold nanoparticles. Two different patterns of nanoparticle size evolution were obtained; the size evolution trend below 1 mM chloroauric acid concentration was found to be different from the one obtained at gold chloride concentrations higher than or equal to 1 mM. In case of sizes obtained for less than 1 mM gold chloride concentration, a general decrease in particle size was observed with increase in gold salt concentration. On the contrary, for the particles synthesised using chloroauric acid concentrations higher than or equal to 1 mM, with increase in gold salt concentration, a general increase in nanoparticle diameter was seen. For the molarities 0.2 and 0.5 mM, with increase in tannic acid/ chloroauric acid ratios, first the size decreases and then increases and finally reaches saturation. Particles formed at molarities greater than equal to 1 mM do not exhibit plateaux in their size rather initially decrease and then increase in response to increasing tannic acid/chloroauric acid ratios except for 2 mM concentration at which a small saturation is observed. The findings enumerate that higher gold chloride concentrations leave a significant impact on the sizes of gold nanaparticles obtained using tannic acid as a reducing agent of chloroauric acid solution.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70877475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-09-06DOI: 10.4236/WJNSE.2013.33013
V. Mathur, K. Rathore, K. Sharma
Thick film of Polystyrene (PS)/CdS semiconducting optical nanocomposite has been synthesized by dispersing nanofiller particles of CdS in PS matrix. The nanostructure of the CdS particles has been ascertained through X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). Small angle x-ray scattering analysis has been performed in order to ascertain nanocomposite character of the PS/CdS sample. Scanning Electron Microscopy (SEM) analyses of these samples have been carried out to establish the surface morphology. Optical Absorption Spectroscopy is used to measure the energy band gap of PS/CdS nanocomposite by using Tauc relation whereas Transient Plane Source Technique is used for the determination of thermal conductivity of the prepared samples. The phase transition temperature and elastic response of the prepared samples have been ascertained through Dynamic Mechanical Analyzer (DMA). This study reveals that the thermal conductivity, Young’s modulus and the toughness of the material are greatly influenced by the existence of interfacial energetic interaction between dispersed CdS nanofiller particles and matrix of PS.
{"title":"Evaluation of Energy Band Gap, Thermal Conductivity, Phase Transition Temperature and Elastic Response of PS/CdS Semiconducting Optical Nanocomposite","authors":"V. Mathur, K. Rathore, K. Sharma","doi":"10.4236/WJNSE.2013.33013","DOIUrl":"https://doi.org/10.4236/WJNSE.2013.33013","url":null,"abstract":"Thick film of Polystyrene (PS)/CdS semiconducting optical nanocomposite has been synthesized by dispersing nanofiller particles of CdS in PS matrix. The nanostructure of the CdS particles has been ascertained through X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). Small angle x-ray scattering analysis has been performed in order to ascertain nanocomposite character of the PS/CdS sample. Scanning Electron Microscopy (SEM) analyses of these samples have been carried out to establish the surface morphology. Optical Absorption Spectroscopy is used to measure the energy band gap of PS/CdS nanocomposite by using Tauc relation whereas Transient Plane Source Technique is used for the determination of thermal conductivity of the prepared samples. The phase transition temperature and elastic response of the prepared samples have been ascertained through Dynamic Mechanical Analyzer (DMA). This study reveals that the thermal conductivity, Young’s modulus and the toughness of the material are greatly influenced by the existence of interfacial energetic interaction between dispersed CdS nanofiller particles and matrix of PS.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70877708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-09-06DOI: 10.4236/WJNSE.2013.33015
H. Benabid, M. Ghorab
The motivation of this work was dictated by a concern of using bioaccumulative plant species likely to be used in the technique of bioindication. The obtained results and discussions proposed are approaches of chemist, because the mechanisms of the effect of cadmium on the various plant cells have been widely developed by several biologists. The use of labeled cadmium is important to study the uptake, the translocation and the metabolism at very low levels of this element in plants. Bean (Phaseolus vulgaris), the model chosen for the investigation, was cultivated in vermiculite for 12 days. After this period, plants were transferred into 100 ml flasks containing nutrient solution and radioactive Cd-109 (γ, t1/2 = 461.3 days) with variable activity of: 0.05, 0.1 and 1.0 micro Currie (μCi). Samples were transferred to a growth room and left for periods of 4 and 7 days, then analyzed by the solid scintillation method. The counting was carried out for roots, stems and leaves.
{"title":"Study of the Translocation and Distribution of Cadmium into Bean Plants (Phaseolus vulgaris) Using Labelled Cd-109","authors":"H. Benabid, M. Ghorab","doi":"10.4236/WJNSE.2013.33015","DOIUrl":"https://doi.org/10.4236/WJNSE.2013.33015","url":null,"abstract":"The motivation of this work was dictated by a concern of using bioaccumulative plant species likely to be used in the technique of bioindication. The obtained results and discussions proposed are approaches of chemist, because the mechanisms of the effect of cadmium on the various plant cells have been widely developed by several biologists. The use of labeled cadmium is important to study the uptake, the translocation and the metabolism at very low levels of this element in plants. Bean (Phaseolus vulgaris), the model chosen for the investigation, was cultivated in vermiculite for 12 days. After this period, plants were transferred into 100 ml flasks containing nutrient solution and radioactive Cd-109 (γ, t1/2 = 461.3 days) with variable activity of: 0.05, 0.1 and 1.0 micro Currie (μCi). Samples were transferred to a growth room and left for periods of 4 and 7 days, then analyzed by the solid scintillation method. The counting was carried out for roots, stems and leaves.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70877989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-09-06DOI: 10.4236/WJNSE.2013.33006
A. Lazaro, G. Quercia, H. Brouwers, J. Geus
Nano-silica, one of the substances boosting the field of nanomaterials, can be produced by dissolving olivine in acid. The dissolution of olivine is a convenient alternative route to the existing methods of nano-silica production (neutralization of sodium silicate and flame hydrolysis) because the olivine dissolution is a low temperature process making this method cheaper and greener. Furthermore, this process can use waste olivine materials for the production of nano-silica. The produced nano-silica has a specific surface area between 100 and 400 m 2 /g; a primary particle size between 10 and 25 nm, which is agglomerated in clusters; and an impurity content below 5 wt.%. In addition, olivine nano-silica can be classified as a pozzolanic material with an activity index of 101%. The optimum replacement level of olivine nano-silica in conventional vibrated concrete is around 5% by volume resulting in: 1) a compressive strength increase of 20%; 2) a CO2 emission reduction of 3%. Therefore, the use of the olivine nano-silica in CVC does not only improve the compressive strength but also reduce the CO2 emissions.
{"title":"Synthesis of a green nano-silica material using beneficiated waste dunites and its application in concrete","authors":"A. Lazaro, G. Quercia, H. Brouwers, J. Geus","doi":"10.4236/WJNSE.2013.33006","DOIUrl":"https://doi.org/10.4236/WJNSE.2013.33006","url":null,"abstract":"Nano-silica, one of the substances boosting the field of nanomaterials, can be produced by dissolving olivine in acid. The dissolution of olivine is a convenient alternative route to the existing methods of nano-silica production (neutralization of sodium silicate and flame hydrolysis) because the olivine dissolution is a low temperature process making this method cheaper and greener. Furthermore, this process can use waste olivine materials for the production of nano-silica. The produced nano-silica has a specific surface area between 100 and 400 m 2 /g; a primary particle size between 10 and 25 nm, which is agglomerated in clusters; and an impurity content below 5 wt.%. In addition, olivine nano-silica can be classified as a pozzolanic material with an activity index of 101%. The optimum replacement level of olivine nano-silica in conventional vibrated concrete is around 5% by volume resulting in: 1) a compressive strength increase of 20%; 2) a CO2 emission reduction of 3%. Therefore, the use of the olivine nano-silica in CVC does not only improve the compressive strength but also reduce the CO2 emissions.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70877276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-06-18DOI: 10.4236/WJNSE.2013.32004
B. Ahmadi, Ehsan R. Mafi, Tahereh Samaee Yekta, Iman R. Mafi, S. M. Kasiriha
In the present investigation, the effect of two different mineral nano clays and a synthetic nano layered silicate on the properties of a transparent polyurethane resin has been studied. Both high rotator Torusmill and high intensity ultrasonic deagglomerator are utilized for the dispersion process. Observations by means of the X-ray diffraction technique indicate the presence of different dispersion status of nano layers in polymer matrix. The optical effect of nano-filled clear coat was studied using goniospectrophotometer and compared with a blank clear coat to determine if it can be identified by human eye. Scratch and mar resistance tests presented considerable improvement. Gloss retention against rubbing increased significantly in the presence of merely 3 wt% of synthetic nano-filler.
{"title":"Optical and Mechanical Study of Mineral and Synthetic Nano Layered Silicate Reinforced Polyurethane Resin","authors":"B. Ahmadi, Ehsan R. Mafi, Tahereh Samaee Yekta, Iman R. Mafi, S. M. Kasiriha","doi":"10.4236/WJNSE.2013.32004","DOIUrl":"https://doi.org/10.4236/WJNSE.2013.32004","url":null,"abstract":"In the present investigation, the effect of two different mineral nano clays and a synthetic nano layered silicate on the properties of a transparent polyurethane resin has been studied. Both high rotator Torusmill and high intensity ultrasonic deagglomerator are utilized for the dispersion process. Observations by means of the X-ray diffraction technique indicate the presence of different dispersion status of nano layers in polymer matrix. The optical effect of nano-filled clear coat was studied using goniospectrophotometer and compared with a blank clear coat to determine if it can be identified by human eye. Scratch and mar resistance tests presented considerable improvement. Gloss retention against rubbing increased significantly in the presence of merely 3 wt% of synthetic nano-filler.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70877058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-06-18DOI: 10.4236/WJNSE.2013.32005
M. Mahmoodan, H. Aliakbarzadeh, F. Shahri
The effect of addition of metallic carbides Cr3C2 and Cr3C2 + VC on structure and mechanical properties of WC-10 wt% Co nanocomposites have been studied. After preparing and compacting of the powders under pressure of 200 MPa, the samples were sintered at temperatures of 1370°C, 1410°C and 1450°C for 1 hour. Microstructural examinations by SEM show that the average grain size obtained for Cr3C2 + VC added alloys reduced 50 percent and also grain size distribution was narrower compared to those samples without grain growth inhibitors. Furthermore, co-addition of Cr3C2 and VC rise to a higher Vickers hardness and fracture toughness of the sintered alloys at 1410°C.
{"title":"Effect of Cr 3 C 2 and VC on the Mechanical and Structural Properties of Sintered WC-10wt%Co Nano Powders","authors":"M. Mahmoodan, H. Aliakbarzadeh, F. Shahri","doi":"10.4236/WJNSE.2013.32005","DOIUrl":"https://doi.org/10.4236/WJNSE.2013.32005","url":null,"abstract":"The effect of addition of metallic carbides Cr3C2 and Cr3C2 + VC on structure and mechanical properties of WC-10 wt% Co nanocomposites have been studied. After preparing and compacting of the powders under pressure of 200 MPa, the samples were sintered at temperatures of 1370°C, 1410°C and 1450°C for 1 hour. Microstructural examinations by SEM show that the average grain size obtained for Cr3C2 + VC added alloys reduced 50 percent and also grain size distribution was narrower compared to those samples without grain growth inhibitors. Furthermore, co-addition of Cr3C2 and VC rise to a higher Vickers hardness and fracture toughness of the sintered alloys at 1410°C.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70877173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-31DOI: 10.4236/WJNSE.2013.31003
M. Mustafa, T. Bhat, M. R. Beigh
This paper investigates the threshold voltage sensitivity to metal gate work-function for n-channel double gate fin field-effect transistor (FinFET) structures and evaluates the short channel performance of the device using threshold voltage dependence on metal gate work-function analysis. We carried out the study for a double gate n-channel fin field-effect transistor (n-FinFET) with parameters as per the projection report of International Technology Roadmap for Semiconductors, ITRS-2011 for low standby power (LSTP) 20 nm gate length technology node. In the present study device simulation have been carried out using PADRE simulator from MuGFET, which is based on the drift-diffusion theory. Our results show the accuracy and validity of classical drift-diffusion simulation results for transistor structures with lateral dimensions 10nm and above. The subthreshold behavior of device improves with increased metal gate work-function. The results also show that a higher gate work-function (≥5 eV) can fulfill the tolerable off-current as projected in ITRS 2011 report. The SCE in FinFET can reasonably be controlled and improved by proper adjustment of the metal gate work-function. DIBL is reduced with the increase in gate work function.
{"title":"Threshold Voltage Sensitivity to Metal Gate Work-Function Based Performance Evaluation of Double-Gate n-FinFET Structures for LSTP Technology","authors":"M. Mustafa, T. Bhat, M. R. Beigh","doi":"10.4236/WJNSE.2013.31003","DOIUrl":"https://doi.org/10.4236/WJNSE.2013.31003","url":null,"abstract":"This paper investigates the threshold voltage sensitivity to metal gate work-function for n-channel double gate fin field-effect transistor (FinFET) structures and evaluates the short channel performance of the device using threshold voltage dependence on metal gate work-function analysis. We carried out the study for a double gate n-channel fin field-effect transistor (n-FinFET) with parameters as per the projection report of International Technology Roadmap for Semiconductors, ITRS-2011 for low standby power (LSTP) 20 nm gate length technology node. In the present study device simulation have been carried out using PADRE simulator from MuGFET, which is based on the drift-diffusion theory. Our results show the accuracy and validity of classical drift-diffusion simulation results for transistor structures with lateral dimensions 10nm and above. The subthreshold behavior of device improves with increased metal gate work-function. The results also show that a higher gate work-function (≥5 eV) can fulfill the tolerable off-current as projected in ITRS 2011 report. The SCE in FinFET can reasonably be controlled and improved by proper adjustment of the metal gate work-function. DIBL is reduced with the increase in gate work function.","PeriodicalId":66816,"journal":{"name":"纳米科学与工程(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70877435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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