Phase transformation of single crystal β-tungsten nanorods at elevated temperatures

Karabacak, Tansel; Wang, Pei-I; Wang, G.-C.; Lu, Toh‐Ming

doi:10.1016/j.tsf.2005.06.059

Cited by 45 publications

(25 citation statements)

References 17 publications

(21 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2a, the top of the vertical nanorods has a pyramidal shape with four facets, which indicates that an individual nanorod has a single crystal structure. This observation was confirmed by previous studies [12][13][14] which reported that individual metallic nanorods fabricated by GLAD are typically single crystal. Single crystal rods do not have any interior grain boundaries and have faceted sharp tips.…”

Section: Nanostructure Depositionsupporting

confidence: 87%

A Compact Nanostructure Enhanced Heat Sink With Flow in a Rectangular Channel

Şeşen

Kosar

Koşar

et al. 2010

ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, Volume 2

Self Cite

View full text Add to dashboard Cite

This paper reports a compact nanostructure based heat sink. The system has an inlet and an outlet valve similar to a conventional heat sink. From the inlet valve, pressurized deionized-water is propelled into a rectangular channel (of dimensions 24mmx59mmx8mm). This rectangular channel houses a nanostructured plate, on which ~600 nm long copper nanorod arrays with an average nanorod diameter of 150 nm are integrated to copper thin film coated on silicon wafer surface. Forced convective heat transfer characteristics of the nanostructured plate are investigated using the experimental setup and compared to the results from a flat plate of copper thin film deposited on silicon substrate. Nanorod arrays act as fins over the plate which enhances the heat transfer from the plate.Excess heat generating small devices are mimicked through a small heat generator placed below the nanostructured plate.Constant heat flux is applied through the heat generator. Thermocouples placed on the heater surface are utilized to gather the surface temperature data. Flow rate and constant heat flux values are varied in order to obtain the correlation between heat removal rate and input power. In this study, it was proved that nanostructured surfaces have the potential to be a useful in cooling of small and excessive heat generating devices such as MEMS (Micro Electro Mechanical Systems) and micro-processors.

show abstract

Section: Nanostructure Depositionsupporting

confidence: 87%

A Compact Nanostructure Enhanced Heat Sink With Flow in a Rectangular Channel

Şeşen

Kosar

Koşar

et al. 2010

ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, Volume 2

Self Cite

View full text Add to dashboard Cite

show abstract

“…2a, the top of the vertical nanorods has a pyramidal shape with four facets, which indicates that an individual nanorod has a single crystal structure. This observation was confirmed by previous studies [16][17][18] which reported that individual metallic nanorods fabricated by GLAD are typically single crystal. Single crystal rods do not have any interior grain boundaries and have faceted sharp tips.…”

Section: Nanostructure Depositionsupporting

confidence: 87%

Submerged Jet Impingement Cooling of a Nanostructured Plate

Şeşen

Koşar

Demir

et al. 2010

Volume 7: Fluid Flow, Heat Transfer and Thermal Systems, Parts a and B

Self Cite

View full text Add to dashboard Cite

In this paper, the results of a series of heat transfer experiments conducted on a compact electronics cooling device based on single phase jet impingement techniques are reported. Deionized-water is propelled into four microchannels of inner d ameter 685µm wh ch are used as nozzles and located at a nozzle to surface distance of 2.5mm. The generated jet impingement is targeted through these channels towards the surface of a nanostructured plate. This plate of size 20mmx20mm consisted of ~600 nm long copper nanorod arrays with an average nanorod diameter of ~150 nm, which were integrated on top of a silicon wafer substrate coated with a copper thin film layer (i.e. Cu-nanorod/Cu-film/Silicon-wafer). Heat removal characteristics induced through jet impingement are investigated using the nanostructured plate and compared to results obtained from a flat plate of copper thin film coated on silicon wafer surface. Enhancement in heat transfer up to 15% using the nanostructured plate has been reported in this paper.Heat generated by small scale electronic devices is simulated using a thin film heater placed on an aluminum base. Surface temperatures are recorded by a data acquisition system with the thermocouples integrated on the surface at various locations. Constant heat flux provided by the film heater is delivered to the nanostructured plate placed on top of the base.Volumetric flow rate and heat flux values were varied in order to better characterize the potential enhancement in heat transfer by nanostructured surfaces.

show abstract

“…The XRD patterns shown in Fig. 2 confirmed the α -Ta, β -Ta, α -W, and βα -W films151617. At least two samples were subjected to the CISP measurement for each film.…”

Section: Resultsmentioning

confidence: 54%

Current-induced spin polarization on metal surfaces probed by spin-polarized positron beam

Zhang

Yamamoto

Fukaya

et al. 2014

Sci Rep

View full text Add to dashboard Cite

Current-induced spin polarization (CISP) on the outermost surfaces of Au, Cu, Pt, Pd, Ta, and W nanoscaled films were studied using a spin-polarized positron beam. The Au and Cu surfaces showed no significant CISP. In contrast, the Pt, Pd, Ta, and W films exhibited large CISP (3~15% per input charge current of 105 A/cm2) and the CISP of Ta and W were opposite to those of Pt and Pd. The sign of the CISP obeys the same rule in spin Hall effect suggesting that the spin-orbit coupling is mainly responsible for the CISP. The magnitude of the CISP is explained by the Rashba-Edelstein mechanism rather than the diffusive spin Hall effect. This settles a controversy, that which of these two mechanisms dominates the large CISP on metal surfaces.

show abstract

Phase transformation of single crystal β-tungsten nanorods at elevated temperatures

Cited by 45 publications

References 17 publications

A Compact Nanostructure Enhanced Heat Sink With Flow in a Rectangular Channel

A Compact Nanostructure Enhanced Heat Sink With Flow in a Rectangular Channel

Submerged Jet Impingement Cooling of a Nanostructured Plate

Current-induced spin polarization on metal surfaces probed by spin-polarized positron beam

Contact Info

Product

Resources

About