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Updated: May 13, 2026

The Frequency Domain Thermoreflectance Technique for Thermal Property Measurements
Published on: December 5, 2025
Frequency domain analysis of spreading-constriction thermal impedance
Francesco Casalegno1, Andrea De Marchi, Valter Giaretto
1Dipartimento di Matematica - Politecnico di Torino - C.so Duca degli Abruzzi, 24, 10129 Torino, Italy.
Abstract:
Spreading-constriction effects are analyzed in the frequency domain. The existence of a half-pole altering the steady state solution at high frequencies is pointed out. Application to the case of thermoelectric devices allows direct comparison with experimental data because thermal quantities can be measured as electrical signals at the very spot where spreading takes place. Good agreement with theory is shown here for a thermoelectric device in which the particular constriction geometry enhances its effect, making easily observable the difference between frequency domain and the steady state approaches.
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