ECI Digital Archives

Title

Characterizing novel transducers for high temperature thermal measurements using time domain thermoreflectance

Authors

Christina M. Rost, Department of Mechanical & Aerospace Engineering, University of VirginiaFollow
Lavina Backman, Department of Mechanical & Aerospace Engineering, University of Virginia
Elizabeth J. Opila, Department of Mechanical & Aerospace Engineering, University of Virginia
Patrick E. Hopkins, Department of Mechanical & Aerospace Engineering, University of Virginia
Kevin Ferri, Department of Materials Science & Engineering, North Carolina State University
Jon-Paul Maria, Department of Materials Science & Engineering, North Carolina State University
Trent Borman, Department of Materials Science & Engineering, North Carolina State University
Charlotte Dawes, Department of Materials Science & Engineering, North Carolina State University

Conference Dates

September 17-20, 2017

Abstract

Time domain thermoreflectance (TDTR) is an optical pump-probe technique used to measure thermal properties of material systems. Samples are typically coated with a thin metal transducer layer, such as aluminum or gold. At temperatures approaching 2,000°C, most transducers become limited by melting temperature, chemical reactions, or other phase transitions. Hafnium Nitride (HfN) is a conductive ceramic with a melting point exceeding 3300°C. It is estimated to have a constant reflectance of 17% and 64% at 400nm and 800nm, respectively. Iridium (Ir) has a melting temperature of 2,447°C. Our work characterizes the thermal properties of HfN and Ir, respectively, and investigates their viability as transducers for TDTR measurements at high temperatures to the point of thermodynamically-driven failure. Thermal conductivity is measured as a function of temperature for HfN and Ir, respectively, and thermoreflectance coefficients are measured and compared to that of typical transducers. Thermal conductivities for MgO, Al₂O₃, SiO₂, and diamond substrates are measured using the aforementioned thin films as transducers to test material reliability. Results and implications for future high temperature TDTR measurements are discussed.

This work is supported by the U.S. Office of Naval Research MURI program (grant No. N00014-15- 1-2863).

Recommended Citation

Christina M. Rost, Lavina Backman, Elizabeth J. Opila, Patrick E. Hopkins, Kevin Ferri, Jon-Paul Maria, Trent Borman, and Charlotte Dawes, "Characterizing novel transducers for high temperature thermal measurements using time domain thermoreflectance" in "Ultra-High Temperature Ceramics: Materials for Extreme Environment Applications IV", Jon Binner, The University of Birmingham, Edgbaston, United Kingdom Bill Lee, Imperial College, London, United Kingdom Eds, ECI Symposium Series, (2017). https://dc.engconfintl.org/uhtc_iv/14