Title :
Thermal Properties of Silicon Nitride Beams Below One Kelvin
Author :
Wang, G. ; Yefremenko, V. ; Novosad, V. ; Datesman, A. ; Pearson, J. ; Divan, R. ; Chang, C.L. ; Bleem, L. ; Crites, A.T. ; Mehl, J. ; Natoli, T. ; McMahon, J. ; Sayre, J. ; Ruhl, J. ; Meyer, S.S. ; Carlstrom, J.E.
Author_Institution :
Mater. Sci. Div., Argonne Nat. Lab., Argonne, IL, USA
fDate :
6/1/2011 12:00:00 AM
Abstract :
We have investigated thermal properties of 1 μm thick silicon nitride beams of different lateral dimensions. We measured the thermal conductance by simultaneously employing a TES both as a heater and as a sensor. Based upon these measurements, we calculate the thermal conductivity of the beams. We utilize a boundary limited phonon transport model and assume a temperature independent phonon mean free path. We find that the thermal conductivity is determined by the fraction of diffusive reflection at surface. The following results are obtained from 0.30 K to 0.55 K: the volume heat capacity is 0.082T+0.502T3 J/m3-K . The width dependent phonon mean free path is 6.58 μm, 9.80 μm and 11.55 μm for 10 μm, 20 μm and 30 μm beams respectively at a 29% surface diffusive reflection.
Keywords :
carrier mean free path; silicon compounds; specific heat; superconducting transitions; thermal conductivity; Si3N4; TES; boundary limited phonon transport model; lateral dimensions; size 1 mum; surface diffusive reflection; temperature 0.3 K to 0.55 K; thermal conductivity; thermal properties; thick silicon nitride beams; volume heat capacity; width dependent phonon mean free path; Conductivity; Heating; Phonons; Silicon; Temperature measurement; Thermal conductivity; Heat transport; phonons; superconducting transition edge sensor; thermal conductivity;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2010.2089407
