Onset of size effect in lattice thermal conductivity of thin films

2013 ◽  
Vol 113 (11) ◽  
pp. 113511 ◽  
Author(s):  
A. A. Maznev
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Size Effect ◽  
Lattice Thermal Conductivity ◽  
Conductivity Of Thin Films

Cross-plane thermal conductivity of thin films characterized by Flash DSC measurement

2019 ◽  
Vol 677 ◽  
pp. 21-25 ◽  
Author(s):  
Yucheng He ◽  
Xiaoheng Li ◽  
Ling Ge ◽  
Qinyun Qian ◽  
Wenbing Hu
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Conductivity Of Thin Films

New device and method for measuring thermal conductivity of thin-films

2006 ◽  
Vol 45 (3) ◽  
pp. 313-318 ◽  
Author(s):  
Chelakara S. Subramanian ◽  
Tahani Amer ◽  
Billy T. UpChurch ◽  
David W. Alderfer ◽  
Cecil Burkett ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
New Device ◽  
Conductivity Of Thin Films

MeV Ion-Beam Bombardment Effects on The Thermoelectric Figures of Merit of Zn4Sb3 and ZrNiSn-Based half-heusler compounds

2007 ◽  
Vol 1020 ◽  
Author(s):  
S. Budak ◽  
S. Guner ◽  
C. Muntele ◽  
C. C. Smith ◽  
B. Zheng ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Measurement System ◽  
Ion Beam ◽  
Electrical Energy ◽  
Figures Of Merit ◽  
Material Systems ◽  
The Cross ◽  
Conductivity Of Thin Films

AbstractSemiconducting â-Zn4Sb3and ZrNiSn-based half-heusler compound thin films were prepared by co-evaporation for the application of thermoelectric (TE) materials. High-purity solid zinc and antimony were evaporated by electron beam to grow the â-Zn4Sb3thin film while high-purity zirconium powder and nickel tin powders were evaporated by electron beam to grow the ZrNiSn-based half-heusler compound thin film. Rutherford backscattering spectrometry (RBS) was used to analyze the composition of the thin films. The grown thin films were subjected to 5 MeV Si ions bombardments for generation of nanostructures in the films. We measured the thermal conductivity, Seebeck coefficient, and electrical conductivity of these two systems before and after 5 MeV Si ions beam bombardments. The two material systems have been identified as promising TE materials for the application of thermal-to-electrical energy conversion, but the efficiency still limits their applications. The electronic energy deposited due to ionization in the track of MeV ion beam can cause localized crystallization. The nanostructures produced by MeV ion beam can cause significant change in both the electrical and the thermal conductivity of thin films, thereby improving the efficiency. We used the 3ù-method measurement system to measure the cross-plane thermal conductivity ,the Van der Pauw measurement system to measure the cross-plane electrical conductivity, and the Seebeck-coefficient measurement system to measure the cross-plane Seebeck coefficient. The thermoelectric figures of merit of the two material systems were then derived by calculations using the measurement results. The MeV ion-beam bombardment was found to decrease the thermal conductivity of thin films and increase the efficiency of thermal-to-electrical energy conversion.

Onset of size effects in lattice thermal conductivity and lifetime of low-frequency thermal phonons

2012 ◽  
Vol 1404 ◽  
Author(s):  
A.A. Maznev
Keyword(s):  
Thin Film ◽  
Thermal Conductivity ◽  
Size Effects ◽  
Lattice Thermal Conductivity ◽  
Low Frequency ◽  
Square Root ◽  
Relaxation Rates ◽  
Frequency Limit ◽  
Conductivity Of Thin Films ◽  
Closed Form Formula

ABSTRACTThe onset of size effects in phonon-mediated thermal transport along a thin film at temperatures comparable or greater than the Debye temperature is analyzed theoretically. Assuming a quadratic frequency dependence of phonon relaxation rates in the low-frequency limit, a simple closed-form formula for the reduction of the in-plane thermal conductivity of thin films is derived. The effect scales as the square root of the film thickness, which leads to the prediction of measurable size-effects even at “macroscopic” distances ~100 μm. However, this prediction needs to be corrected to account for the deviation from the ω−2 dependence of phonon lifetimes at sub-THz frequencies due to the transition from Landau-Rumer to Akhiezer mechanism of phonon dissipation.

Using pulsed and modulated photothermal radiometry to measure the thermal conductivity of thin films

2013 ◽  
Vol 556 ◽  
pp. 1-5 ◽  
Author(s):  
Andrzej Kusiak ◽  
Jiri Martan ◽  
Jean-Luc Battaglia ◽  
Rostislav Daniel
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Photothermal Radiometry ◽  
Conductivity Of Thin Films
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