ジルコンチタン酸鉛圧電セラミックスにおける非線形定数の直流バイアス依存性

Abstract

In order to clarify the occurrence mechanism of nonlinear phenomena, dc-bias dependence and aging characteristics of the nonlinear coefficients of second-higher and third-higher terms were measured in piezoelectric rectangular vibrators. The two nonlinear coefficients of second-and third-higher terms were contrasted sharply in their dc-bias dependence and aging characteristics. These contrasting dependences originate from the difference in the occurrence mechanism of harmonic voltages, that determines the values of the second-and third-higher nonlinear coefficients. The difference in the occurrence mechanism was discussed from the viewpoint of non-180? domain-wall motion. Key-words : Nonlinear piezoelectric coefficient, Lead zirconate titanate, High-power vibration, Piezoelectric vibrator, dc-bias dependence, Aging 1. Introduction When lead zirconate titanate PZT piezoelectric ceramics are driven with a high power at frequencies around the resonance frequency after poling treatment, nonlinear phenomena such as current jumping and harmonic voltage generations are observed. These nonlinear phenomena restrict the operating range of devices, and simultaneously prevent operation stability.It is difficult to perform perfect poling in PZT ceramics for polycrystals. Nonoriented domains partially remain after poling treatment. We measured nonlinear coefficients of Pb Mg 13 Nb 23 O 3 PMN ceramics, which are paraelectric at room temperature, in order to investigate the influence of domains on nonlinear phenomena. The piezoelectric resonance of PMN ceramics was realized by applying a dc-bias field of 1400 Vmm. The nonlinear coefficient of the thirdhigher term of PMN ceramics without any domains was consequently about 1100 compared to that of PZT ceramics. Furthermore, current jumping appeared markedly in PZT but did not appear in PMN.1 These facts show that nonlinear phenomena are dominated by the existence of domains.In the development of practical materials suitable for high-power devices, the vibration velocity dependence of the mechanical quality factor and elastic constants were investigated.2 ,3 If the vibration velocity exceeds a threshold value, PZT ceramics become elastically soft and their mechanical quality factor decreases at the same time. This is the nonlinearity that observed as the change of linear coefficients. Since the 180c domain wall motion exerts no influence on the strain, the decrease in the mechanical quality factor and the change in elastic constant were probably caused by the motion of non-180c domain walls.

Relationship between Nonlinear Piezoelectricity and Decrease of Mechanical Quality Factor in Pb(Mn1/3Sb2/3)O3–PbZrO3–PbTiO3 Piezoelectric Ceramics Driven at High Power

“…[1][2][3][4] The D31 was obtained by measuring the third-harmonic voltage generated during constant-current driving. [5][6][7][8][9][10] The waveforms of sample current and sample voltage were simultaneously accumulated into a digital storage scope (Lecroy LT344) in the constant-current-measurement circuit, as shown in Fig. 2(b).…”

“…The n is the conversion factor obtained by considering the electrode configuration, and is equal to 3 4 =128 when the rectangular samples have whole-surface electrodes. 7) The 3rd nonlinear piezoelectric equation transformed into the h-form equation from the g-form equation is expressed as [5][6][7][8][9][10][11])…”

“…On the other hand, we quantitatively studied the piezoelectric nonlinearity by defining the intrinsic nonlinear piezoelectric coefficient of the third-higher term as the material constant, D31 . [5][6][7][8][9][10][11] Since the resistance component increases in the samples driven at a high power due to the contribution of the imaginary component of the nonlinear piezoelectric constant, a more significant decrease of Q m is predicted in the samples with larger D31 . However, the relationship between the nonlinear piezoelectricity quantified by D31 and the Q m decrease has not been investigated.…”

Effect of Sr Substitution on a Nonlinear Piezoelectric Coefficient of Third-Higher Term in Lead–Zirconate–Titanate-based Piezoelectric Ceramics

“…Because D31 is due to the asymmetry of non-180 domainwall movement in both the extension and contraction of ceramic vibrators, it is accordingly not the coefficient for quantitatively evaluating the magnitude of nonlinearity. 28) The coefficient for quantitatively evaluating nonlinearity is D31 .…”

Electric bias dependence of piezoelectric wave reflection upon a rotating half‐plane

“…Yang and Hu presented a detailed review on the mechanics of small‐amplitude motions superposed on finite biasing or initial fields in an electroelastic body. Tashiro et al . investigated the dc‐bias dependence and aging characteristics of the nonlinear coefficients of the second‐ and third‐higher terms in piezoelectric rectangular vibrators.…”