In-situ observation of fatigue crack growth for ${langle001rangle}$ -oriented rhombohedral Pb(Mg1/3 Nb2/3)O3–PbTiO3 ferroelectric single crystal

摘要

In-situ observation of the electrically induced fatigue crack growth is carried out for ${langle001rangle}$ -oriented (Pb(Mg1/3Nb2/3)O3)0.72–(PbTiO3)0.28 (PMN-28PT) ferroelectric single crystals under alternating electric field. It is found that apparent crack growth takes place even though the peak value of the applied electric field is below E c. The crack propagation is a repeated process of advancement in small increments, followed by a sudden increase in the crack length. When the crack tip pops-in, there is a tendency for branching. The test data suggest that the variation of the crack boundary condition may contribute to the observed electrically induced crack growth behavior.