论文部分内容阅读
根据压电本构方程和细观力学统计平均法,采用X射线衍射(XRD)测量Pb(Zr0.52Ti0.48)O3(PZT)铁电薄膜的残余应力。考虑激光沉积生长过程中,薄膜相变应力、热应力和本征应力对自由能的贡献,分析薄膜晶胞在晶体坐标系上的应力应变状态。由坐标转换将晶胞残余应力从晶体坐标系转换到样品坐标系得到任意取向晶粒的残余应力,通过取向平均得到薄膜样品坐标系上的残余应力。用脉冲激光沉积法(PLD)制备了不同厚度的PZT薄膜。利用X射线衍射分别采用细观力学统计平均法和传统sin2ψ法测量了PZT薄膜的残余应力。结果表明,两种结果在数值上是比较接近的(绝对差范围0.3~16.6 MPa),残余压应力随着膜厚的增加从96 MPa左右减少到45 MPa左右。最后讨论了细观力学统计平均法的优缺点。
The residual stress of Pb (Zr0.52Ti0.48) O3 (PZT) ferroelectric thin films was measured by X-ray diffraction (XRD) according to the piezoelectric constitutive equation and the statistical method of meso-mechanics. Considering the contribution of the phase transformation stress, thermal stress and intrinsic stress on the free energy during laser deposition growth, the stress-strain state of the thin film cell in the crystal coordinate system is analyzed. The residual stress in the film sample coordinate system is obtained by the coordinate transformation after the residual stress of the unit cell is transformed from the crystal coordinate system to the sample coordinate system to obtain the residual stress of the grain oriented at any orientation. Different thicknesses of PZT films were prepared by pulsed laser deposition (PLD). The residual stress of PZT thin film was measured by X-ray diffraction using the statistical method of meso-mechanics and the traditional sin2ψ method respectively. The results show that the two results are close in numerical value (the range of absolute difference is 0.3 ~ 16.6 MPa). The residual compressive stress decreases from about 96 MPa to about 45 MPa with the increase of film thickness. Finally, the advantages and disadvantages of the statistical averaging method of meso-mechanics are discussed.