Effect of uniaxial stress on the polarization of SrBi2Ta2O9 thin films

The effect of uniaxial stress on the ferroelectric properties of SrBi2Ta2O9 films with different thicknesses (330, 440, and 660 nm) has been investigated. It is found that both the remnant polarization (Pr) and the spontaneous polarization (Ps) decrease with the application of compressive stress, but increase with the application of tensile stress. And the changes of Pr and Ps become larger for thicker films. For the 660 nm film, as the stress changed from -100 MPa (compressive) to +100 MPa (tensile), the Pr increases from -1.8% to +1.8%. Testing voltages in the range of 3-6 V showed no impact on the amplitude of change on the polarization under mechanical stress. Mechanical stress also did not show significant impact on the coercive field. (C) 2000 American Institute of Physics. [S0003-6951(00)01221-3].