Local measurements of domain wall-induced self-heating in released PbZr_0.52Ti_0.48O₃films

The motion of domain walls in lead zirconate titanate (PZT) produces both nonlinearity and hysteresis. While measurements of the resulting self-heating under an electric field drive are well known in bulk ferroelectric ceramics, self-heating effects in PZT films may differ from those in bulk ceramics due to a combination of reduced domain wall motion, differences in heat dissipation associated with substrates or passive elastic layers, and differences in typical drive fields. Here, it is shown that the thermal imaging of the test structures of PZT piezoelectric microelectromechanical systems using techniques such as infrared thermography and thermoreflectance thermal imaging suffers from motion-induced artifacts. These limitations were overcome via nanoparticle-assisted Raman thermometry with a spatial resolution of ∼1 μm. To acquire the local temperature distribution quantitatively, anatase nanoparticles were distributed across the electrodes and actuating PZT diaphragm. The temperature rise of the test structures increased as the operating frequency, voltage amplitude, and slew rate increased. As expected, the largest temperature rises were induced due to self-heating associated with domain switching under bipolar operation. In addition, a higher voltage amplitude testing revealed non-uniform temperature distributions across the piezoelectric actuator, suggesting that AC Joule heating can induce significant heat generation (ΔT ∼30 K) under high electric fields (∼390 kV/cm).