Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    High resolution transmission electron microscopy and magnetic properties of nanocrystalline iron particles with oxidized and nitrided surfaces (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 4793-4799 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Nanocrystalline iron powders were produced by means of gas condensation. Pure nitrogen, or oxygen, or air, was introduced into the as-made powders before they were taken from the chamber. Different atmospheres produced different layer structures around the iron particles. A high resolution transmission electron microscope was used to analyze the crystal structure and a vibrating-sample magnetometer was used to measure the magnetic properties of nanocrystalline iron particles. The results showed that a layer of amorphous or nanocrystalline structure was formed initially on the surface of iron particles. This thin amorphous layer crystallized into Fe3O4 after annealing under electron irradiation when the introduced atmosphere was pure oxygen or air. However, it formed a passivated layer of ζ-Fe2N when nitrogen was introduced. A hydrogen-reducing process was employed to remove the oxide layer from the surface of nanocrystalline iron particles. The clean surface led to increased magnetization. The exchange anisotropy between the iron core and the superficial iron oxide or nitride shell was observed as the sample was cooled in an applied field of 10 kOe from room temperature to 5 K. The shift of the hysteresis loop caused by exchange anisotropy was 16% for the nitride shell and 8% for the oxide shell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.358491
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Amorphization of transition metal-Si alloy powders by mechanical alloying (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 1362-1365 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Amorphization of TM-Si (TM: trasition metal) alloy powders by mechanical alloying has been systematically investigated. Pure element powder mixtures were mechanically alloyed for ten hours with a high energy ball mill. The results show that amorphous metallic silicide powders were successfully synthesized in Ti-Si, Zr-Si, Nb-Si, and Ta-Si systems. Prediction of the amorphization range of mechanically alloyed TM-Si powders by the Miedema model is inappropriate. The possible criteria for the amorphization of TM3Si powders after mechanical alloying 10 h in a shaker ball mill are (a) the free energy of amorphous state of TM3Si powders is less than −31.95 kJ/mole, and (b) the silicon to trasition metal atomic radius ratio is less than 0.985.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.354893
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Microstructure and Properties of Vacuum Hot-Pressing SiC/ Ti-Cu-Ni-Sn Bulk Metallic Glass Composites (2007)
    s.l. ; Stafa-Zurich, Switzerland
    Key engineering materials Vol. 351 (Oct. 2007), p. 26-30 
    Details
    ISSN: 1013-9826
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: In the present study, Ti50Cu28Ni15Sn7 metallic glass and its composite powdersreinforced with 4~12 vol% of SiC additions were successfully prepared by mechanical alloying.The as-milled Ti50Cu28Ni15Sn7 and composite powders were then consolidated by vacuum hotpressing into disc compacts with a 10 mm diameter and thickness of 2 mm. The structure of theas-milled powders and consolidated compacts was characterized by X-ray diffraction. While thethermal stability was examined by differential scanning calorimeter. In addition, the mechanicalproperty of the consolidated bulk metallic glass and its composite was evaluated by Vickersmicrohardness tests. In the ball-milled composites, initial SiC particles were homogeneouslydispersed in the Ti-based alloy glassy matrix. The presence of SiC particles did not dramaticallychange the thermal stability of Ti50Cu28Ni15Sn7 glassy powders. BMG composite with submicronSiC particles homogeneously embedded in a highly dense nanocrystalline/amorphous matrix wassuccessfully prepared. A significant hardness increase with SiC additions was noticed forconsolidated composite compacts
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/01/55/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.351.26.pdf
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Multi-Wall Carbon Nanotubes as a Support for Platinum Catalysts for the Hydrodechlorination of Carbon Tetrachloride and Dichlorodifluoromethane (2007)
    s.l. ; Stafa-Zurich, Switzerland
    Solid state phenomena Vol. 128 (Oct. 2007), p. 261-271 
    Details
    ISSN: 1662-9779
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Physics
    Notes: Multi-wall carbon nanotubes (MWCNTs) were used as a support for the deposition ofhighly dispersed platinum. After characterization by several physical techniques, the catalyst wasstudied in reactions for: hydrodechlorination of carbon tetrachloride and the hydrodechlorination ofdichlorodifluoromethane. For the first reaction Pt/MWCNTs were very effective catalysts in termsof both the overall activity and the selectivity to CHCl3; both quantities appeared high and stable.For CCl2F2 hydrodechlorination the catalyst was rather moderate, although very stable, activity andproduct selectivities were established at a constant level in a relatively short time-on-stream. TheMWCNTs-supported Pt particles do not undergo great changes during the reactions, i.e. neithersubstantial metal sintering occurred nor extensive surface carbonization/chloriding took place
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/02/24/transtech_doi~10.4028%252Fwww.scientific.net%252FSSP.128.261.pdf
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Hybrid MOS/CNTs Materials for Gas Sensing (2006)
    s.l. ; Stafa-Zurich, Switzerland
    Solid state phenomena Vol. 111 (Apr. 2006), p. 19-24 
    Details
    ISSN: 1662-9779
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Physics
    Notes: Most of the gases detecting metal oxide semiconductors are operated at temperatures above 250oC. It is not energy efficient for MOS gas sensors to operate at such high temperature. To solve this problem, research and investigations are trying to obtain new MOS sensing materialsthat can operate at ambient temperature. In this study, gas sensing materials consisting of MOS and carbon nanotubes (CNTs) are developed for detecting gases at lower temperature. The hybrid system, MWCNTs/TiO2, demonstrates the possibility of detecting the gases at ambient temperature with high energy efficiency
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/02/22/transtech_doi~10.4028%252Fwww.scientific.net%252FSSP.111.19.pdf
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Process Analysis and Characterization of ASNSS Using Automatic On-Line Measurement (2005)
    s.l. ; Stafa-Zurich, Switzerland
    Key engineering materials Vol. 295-296 (Oct. 2005), p. 381-386 
    Details
    ISSN: 1013-9826
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: This article presents the development of an automatic on-line measurement system for characterizing a nanoparticle manufacturing process known as Arc Spray Nanoparticle Synthesis System (ASNSS). The ASNSS has been developed to generate metal nanoparticles and to explore the optimum system parameters for producing the desired nanopowders. Preliminary experimental results indicate that the size of nanoparticles, widely ranging from 10nm to 300nm, is significantly affected by the process parameters such as operating pressure, temperature, electrical current and type of dielectric liquid used. The on-line measurement system was developed to provide an effective multi-solution for characterizing the nanoparticle synthesis process and for monitoring the manufacturing quality of the ASNSS. Experiments were conducted to identify the optimum sampling period and volume of the particle suspension for accurate sampling and data acquisition. Experimental results revealed that a sampling duration of 20 minutes and a dielectric volume of 40 c.c. can achieve effective data representation while maximizing the sampling efficiency
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/01/50/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.295-296.381.pdf
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Performance of Low Resistivity Electrode Prepared by Electroless Plated for Amorphous Silicon Thin-Film Transistors (2007)
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 561-565 (Oct. 2007), p. 1165-1168 
    Details
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The TFTs array fabrication process for large-area TFT-LCD has been continuouslydeveloped for simplifying processing steps, improving performance and reducing cost in the processof mass production. In this study, the hydrogenated amorphous silicon (a-Si:H) TFTs with lowresistivity electrodes , silver thin films, were prepared by using the selective deposition method thatcombined lift-off and electroless plated processes. This developed process can direct pattern theelectrode of transistor devices without the etching process and provide ease processing steps. Theas-deposited Ag films were annealed at 200 oC for 10 minutes under N2 atmosphere. The resultsshows that the adhesion properties can be enhanced and the resistivity has been improved from 6.0μ,-cm, significantly decrease by 35%, of as-deposited Ag films by annealed. The thickness of Agthin film is about 100 nm and the r. m. s roughness value is 1.54 nm. The a-Si:H TFT with Ag thinfilms as source and drain electrodes had a field effect mobility of 0.18 cm2/Vs, a threshold voltage of2.65 V, and an on/off ratio of 3×104
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/02/17/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.561-565.1165.pdf
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Characterization and Modification of Nanocrystalline Iron Oxide Powders Prepared by an Inert Gas Condensation Technique (2007)
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 561-565 (Oct. 2007), p. 1379-1382 
    Details
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Nanocrystalline iron oxide powders were prepared by an inert gas condensationtechnique under various oxygen partial pressures. The as-prepared nanocrystalline iron oxidepowders were further modified by electroless nickel plating. The as-prepared and modifiednanocrystalline powders were characterized by X-ray diffraction, transmission electron microscopy,and synchrotron X-ray absorption techniques. In addition, magnetic properties of the iron oxidenanoparticles before and after electroless nickel plating were evaluated by vibrating samplemagnetometer. The experimental results show that the as-prepared nanocrystalline iron oxidepowders exhibited a mixture of iron and γ-Fe2O3 phases. TEM observations revealed that oxidationstarted from the surface of the gas-condensed iron nanoparticles. The amount of iron oxideincreased with increasing oxygen partial pressure and was confirmed by synchrotron x-rayabsorption examination. A decrease in saturated magnetization and coercivity of the nanocrystallineiron oxide powders was observed after electroless nickel plating
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/02/18/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.561-565.1379.pdf
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Development of Pressure Technique of Brake Nanofluids from an Arc Spray Nanoparticles Synthesis System (2006)
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 505-507 (Jan. 2006), p. 49-54 
    Details
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The low-pressure control methods for an arc-submerged nanoparicle synthesis system (ASNSS) was proposed and developed for brake nanofluids. In the process, a copper bar is melted and vaporized in insulating liquid for core formation with crystallization suppressed to derive nanofluid that contains nanometer copper particles in DOT3 brake fluid. Two technical advances associated with nanoparticle synthesis were achieved. One is the novel pressure control technique developed for nanoparticle fabrication. The other is the verification that the constant low-operating pressure. Pressure operating plays important role in determining the characteristics of the prepared nanoparticles in brake fluids. From the experimental processes, pressure control of the ASNSS was identified as crucial to success of nanoparticles synthesis. To achieve the desired pressure control, a vacuum chamber was developed as a nanoparticle accumulator and low-pressure reservoir. The chamber was controlled by the proposed flow –valve feedback control system and integrated with the ASNSS. The pressure control equipment of the ASNSS was effectively developed to prepare desired copper-oxide brake nanofluids with well-controlled size
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/02/11/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.505-507.49.pdf
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Amorphization behaviour in mechanically alloyed Ni—Ta powders (1998)
    Springer
    Journal of materials science 33 (1998), S. 235-239 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Amorphization behaviour of NixTa100−x alloy powders synthesized by mechanical alloying mixtures of pure crystalline Ni and Ta powders with a Spex high energy ball mill was studied. The mechanically alloyed powders were amorphous for the composition range between Ni10Ta90 and Ni80Ta20. This range is larger than amorphous alloys prepared by the rapid-quenching process or by electron-gun deposition technique. A supersaturated nickel solid solution formed for Ni-rich composition. The thermal stability has been investigated by differential thermal analysis. The crystallization temperature of amorphous Ni—Ta powders was proportional to the Ta content, and the activation energy of amorphous Ni—Ta powders exhibited a maximum near the eutectic composition. It is found that the amorphization rate at the early stage of the mechanical alloying process was faster in the intermediate compositions than those at both Ni- and Ta-rich compositions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004334805505
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...