Composition dependence of 90° domain switching in Pb(Mg1/3Nb2/3)1−xTixO3 system

Lead magnesium niobate–lead titanate Pb(Mg1/3Nb2/3)1−xTixO3 ceramics of different compositions (x = 0.38–0.50) were prepared by the columbite method. The effect of uniaxial stress on macroscopic properties and microscopic parameters of tetragonal ceramics Pb(Mg1/3Nb2/3)1−xTixO3 was investigated. During the application of stress, the percentage of switched domains (PSD) in Pb(Mg1/3Nb2/3)1−xTixO3 ceramics was evaluated by X-ray diffraction (XRD) patterns. We found that stress depolarization was controlled by 90° domain reorientation, and depends on the tetragonality of the phase. The polarization was simulated from the microscopic data and compared with macroscopic polarization. The good agreement between these two curves underlies a strong correlation between microscopic parameters and macroscopic properties. It is evidenced that the depolarization process under stress is almost exclusively governed by domain switching. The proposed simulation of depolarization under stress is suitable for all tetragonal compositions and can help to understand the mechanism involved in this phenomenon and the effect of dopants on piezoelectric properties. In addition, determination of the spontaneous polarization of the tetragonal composition is performed for compositions where a single crystal with a single domain is not possible. Spontaneous polarization of 0.55PMN–0.45PT and 0.50PMN–0.50PT are found to be 0.48 C m−2 and 0.56 C m−2, respectively.

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