Effect of Hydrostatic Pressure on the Dielectric Response of Pb(Mg1/3Nb2/3)O3 Relaxor

The effect of hydrostatic pressure on the dielectric response of Pb(Mg_1/3Nb_2/3)O₃ relaxor single crystal was studied. An increase in the dispersion of the dielectric anomaly, characteristic of the relaxors, was observed: pressure-induced downward shift of the temperature T _m of permittivity maximum at 1 kHz amounts to dT _m /dp = ? 3.8 K/100 MPa, whereas that measured at 1 MHz equals ? 3.3 K/100 MPa. Analysis of the dielectric response of the highly polarizable Pb(Mg_1/3Nb_2/3)O₃ shows that hydrostatic pressure results in a decrease of the correlation radius r _c of polar nanodomains, as well as their activation energy.