High-frequency response heat flux sensor based on the transverse thermoelectric effect of inclined La1−xCaxMnO3 films

The heat flux sensors composed of inclined epitaxial La1−xCaxMnO3 (LCMO) films have been fabricated on c-axis miscut SrTiO3 (001) single crystal substrates. Based on the transverse thermoelectric (TTE) effect originated from the anisotropic Seebeck coefficient between ab-plane and c-axis of LCMO films, the obvious response voltages perpendicular to the temperature gradient are detected, and their amplitudes show good linearity with heat fluxes. The sensitivities of heat flux sensors are 8.64, 11.88, 12.66, and 14.25 μV/(kW/m2) for LCMO films with inclined 12°, 18°, 20°, and 24°, respectively. Additionally, the response frequency of the sensor reaches ∼300 kHz at −3 dB, which is comparable with the reported TTE heat flux sensors composed of YBa2Cu3O7-δ. The above results demonstrate the potential of the LCMO-based TTE heat flux sensors in high-frequency heat flux measurement.