Thermal tuning of phononic bandstructure in ferroelectric ceramic/epoxy phononic crystal

Thermal tuning of phononic bandgaps in megahertz range was demonstrated in ferroelectric ceramic-based phononic crystal structure. Temperature variation across ferroelectric phase transition, accompanied by substantial changes in acoustic velocities, leads to a shift in the phononic bandstructure of a two-dimensional (Ba,Sr)TiO(3)/epoxy composite sample over a range of 10 degrees C. Experimental results are supported by modelings based on plane-wave expansion calculations. The high tunability of phononic bandstructure is advantageous for active control of ultrasound transmissions.