S. Priya et al., Mechanical aging behavior of oriented Pb(Mg1/3Nb2/3)O-3-PbTiO3 and Pb(Zn1/3Nb2/3)O-3-PbTiO3 single crystals, APPL PHYS L, 79(16), 2001, pp. 2624-2626
The aging characteristics of < 001 > -oriented Pb(Zn1/3Nb2/3)O-3-PbTiO3 (PZ
N-PT) and Pb(Mg1/3Nb2/3)O-3-PbTiO3 (PMN-PT) single crystals have been studi
ed under electrical and mechanical drive. A significant increase in hystere
tic loss and decrease in piezoelectric constant were observed under continu
ous excitation. Systematic investigations of piezoelectric aging were then
performed using a novel mechanical fatigue method. Piezocrystals were place
d between two magnetostrictive plates and clamped. Periodic longitudinal co
mpressive stresses were generated by applying magnetic fields. At both shor
t and long times, the piezoelectric constant was found to decrease slowly.
However, in an intermediate range, a pronounced decrease was observed over
a narrow time range. The dynamics of aging have been shown to scale to a hi
erarchical relaxation process, typical of disordered systems such as random
field and glassy states. (C) 2001 American Institute of Physics.