Frequency Dependence of Coercive Fields of [001]- and [011]-Poled Rhombohedral Pb(In1/2Nb1/2)O₃-Pb(Mg1/3Nb2/3)O₃-PbTiO₃ Single Crystals

Relaxor-PbTiO
₃
(PT-based) ferroelectric single crystals are important for many piezoelectric applications because of their outstanding performances. In order to expand their usage and avoid the failure during application, frequency dependence of coercive fields E
_C
for [001]- and [011]-poled rhombohedral Pb(In
_1/2
Nb
_1/2
)O
₃
-Pb(Mg
_1/3
Nb
_2/3
)O
₃
-PbTiO
₃
(PIN-PMN-PT) single crystals was investigated from the frequency of 1 Hz to 300 kHz by using hysteresis loop measurement (frequency: from 1 Hz to 2 kHz) and a critical value method (frequency: from 5 to 300 kHz). The results showed that the coercive field E
_C
, remnant polarization P
_r
, and saturation polarization P
_s
strongly depended on the crystal orientation and frequency. Compared with the [001]-poled crystals, the [011]-poled PIN-PMN-PT single crystals possessed higher E
_C
, P
_r
, and P
_s
at the same testing frequencies. With increasing frequency from 1 Hz to 300 kHz, the coercive fields E
_C
of the [001]- and [011]-poled PIN-PMN-PT single crystals increased from 4.0 and 4.8 kV/cm to 11.5 and 14.9 kV/cm, respectively. Moreover, the frequency dependence of the coercive fields was found to be consistent with the growth kinetics model, where the coercive fields E
_C
were proportional to f
^β
. This work benefits to the design of piezoelectric devices based on PIN-PMN-PT single crystals operated at high frequencies and high driving fields.