Hafnium nitride films for thermoreflectance transducers at high temperatures: Potential based on heating from laser absorption

Abstract

Time domain thermoreflectance (TDTR) and frequency domain thermoreflectance (FDTR) are common pump-probe techniques that are used to measure the thermal properties of materials. At elevated temperatures, transducers used in these techniques can become limited by melting or other phase transitions. In this work, time domain thermoreflectance is used to determine the viability of HfN thin film transducers grown on SiO2 through measurements of the SiO2 thermal conductivity up to approximately 1000 K. Further, the reliability of HfN as a transducer is determined by measuring the thermal conductivities of MgO, Al2O3, and diamond at room temperature. The thermoreflectance coefficient of HfN was found to be 1.4 × 10−4 K−1 at 800 nm, one of the highest thermoreflectance coefficients measured at this standard TDTR probe wavelength. Additionally, the high absorption of HfN at 400 nm is shown to enable reliable laser heating to elevate the sample temperature during a measurement, relative to other transducers.

Document Details

Document Type
Pub Defense Publication
Publication Date
Oct 09, 2017
Source ID
10.1063/1.5006648

Entities

People

  • Ashutosh Giri
  • Christina M. Rost
  • Elizabeth J. Opila
  • Jeffrey L Braun
  • Jon-Paul Maria
  • Kevin Ferri
  • Lavina Backman
  • Patrick E Hopkins

Organizations

  • North Carolina State University
  • Office of Naval Research Global
  • University of Virginia

Tags

Readers

  • Optical Physics and Photonics.
  • Thermal Physics or Thermal Science.
  • Thin Film Deposition Science.

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers
  • Directed Energy - Pulsed-Laser Deposition