Nonlinearity of strain and strain hysteresis in morphotropic LaSr-doped lead zirconate titanate under unipolar cycling with high electric fields

Abstract

The strain behavior of morphotropic, 1La2Sr-doped lead zirconate titanate was investigated. Particular attention was paid to the electric field induced strain ͑S-E characteristic͒ in the high field range for morphotropic materials having different Zr/ Ti ratios. Unipolar electrical cycles with maximum fields between 1 and 3 kV/ mm were applied to the poled materials under load-free conditions. Strain curves were recorded and the data were evaluated with respect to field dependence of strain and strain hysteresis. Nonlinearity of strain was detected for all materials. Depending on the composition, marked differences were found with respect to the types of nonlinearity. The corresponding data on strain hysteresis indicate that the nonlinearity was due to a loss generating strain mechanism. Therefore the nonlinearity was attributed to domain switching. A phenomenological model is suggested, which is based on the assumptions of a distribution of domain switching over a field range. This field range is characterized by the activation field parameter E a , which is specific for each composition. The model is capable of explaining the types of nonlinearity in strain that have been observed.

Piezoelectric activity of (1-x)[0.35Bi(Mg1/2Ti1/2)O3-0.3BiFeO3-0.35BiScO3] - xPbTiO3 ceramics as a function of temperature

“…Figure 5 presents the % strain vs. electric field from room temperature to 180°C exhibited by poled (1-x) BMTFS -xPT ceramics with 0.46≤x≤0.50 at 50 kV/cm under unipolar drive. At a given field, the strain displayed by the sample approaching E max was lower than the strain departing E max due to strain hysteresis [14]. Figure 6 shows the temperature dependence of % strain and high field piezoelectric coefficient under unipolar drive, d * 33(uni) for compositions with 0.46≤x≤0.50.…”

Both electric field and temperature independent behavior of piezoelectric property of Pb(Ni1/3Nb2/3)O3–PbTiO3

“…The unipolar strain enhancement is approximately linear and slim with electric field for the composition of 0.62PNN-0.38PT, and the maximum strain almost stays the same level in the range of 100 C. For all unipolar cycles the strain curves were evaluated with respect to strain S max at E max and strain hysteresis [4]. The strain hysteresis can be quantified as a ratio of the difference between uppoling and down-poling strains at a half E max to the total strain at the E max [4]. The hysteresis of 0.62PNN-0.38PT is as small as 8% at room temperature.…”

“…There are different types of electric field induced unipolar strain (S-E) curves with rising electric field. For example, the S-E curve bends upwards in LaSr-doped lead zirconate titanate (PZT) with Zr/Ti ratio of 52/48 [4]. Whereas, the S-E curve bends downward in (1 À x)Bi(Ni 1/2 Hf 1/2 )O 3 -xPbTiO 3 system with x = 0.60 [5].…”

Lead-free piezoceramics with giant strain in the system Bi0.5Na0.5TiO3–BaTiO3–K0.5Na0.5NbO3. II. Temperature dependent properties

“…[12][13][14] In the vicinity of T d , the piezoelectric performance may be enhanced, since the strain response can have two separate contributions: an extrinsic contribution due to ferroelectric non-180°domain switching and an intrinsic contribution due to changes in the dimensions of the crystal lattice. 15,16 Indeed, an extremely high strain was observed in lead-free piezoceramics especially with the composition of 0.92BNT-0.06BT-0.02KNN in our previous work. 17 It was proposed that these systems contain a mixture of FE and AFE phases and the high strain was in large part attributed to an AFE-FE phase transition induced by the externally applied electric field.…”