Damping properties of lead metaniobate

Mechanical damping, tan /spl delta/, of lead metaniobate was determined experimentally over a wide range of frequencies. Damping at audio and sub-audio frequency was lower than at ultrasonic frequency. The experiments were conducted in torsion and bending using an instrument capable of determining viscoelastic properties over more than 10 decades of time and frequency. Mechanical damping was higher in bending than torsion at all frequencies. Damping observed in this study at the highest frequencies approaches the high value 0.09 previously observed at ultrasonic frequency.