The anelastic behavior of metaniobate ceramics was studied by measuring the internal friction and oscillation frequency as a function of temperature. Two types of internal friction peak were observed. One type of peak was clearly related to the working process. These peaks were considered to be caused by interactions between dislocations and point defects. The other kind of peak was a broadened Debye relaxation peak. The corresponding activation energy and pre-exponential factor were 1.01eV and 2.5 x 10-12s. This peak was attributed to interactions between domain walls and O vacancies.

Anomalous Internal Friction in Lead Metaniobate Ceramics. L.X.He, C.E.Li, H.X.Yan, T.G.Chen: Journal of Applied Physics, 2000, 87[6], 3186-8