Y.C. Zhou

Residual stress in PZT thin films prepared by pulsed laser deposition

Abstract In this investigation, ferroelectric thin films Pb(Zr x Ti 1− x )O 3 (PZT) with x =0.58 were deposited on Pt/Ti/Si(001) by pulsed laser deposition (PLD). The residual stresses in PZT thin films were measured by an X-ray diffractometer (XRD) and indentation fracture method. In the indentation fracture method, the surface crack model and half-penny crack model were adopted. For PZT thin films with thickness of 0.05 μm, 0.5 μm and 1.0 μm, the residual stresses determined by a half-penny crack model were −74.73 MPa, −22.86 MPa and −14.74 MPa and those measured by XRD method were −57.6 MPa, −48.5 MPa and −25.6 MPa, respectively. The residual stresses determined by a half-penny crack model were closer to the results measured by XRD. A theoretical model is proposed to predict the residual stress in PZT thin film and the analytical results are essentially consistent with the experimental results. The effect of residual stress on piezoelectric properties is also discussed. The good ferroelectrics behaviors were demonstrated ( P r =22–35 μC cm −2 , E c =25–315 kV cm −1 ) by the hysteresis loops.

Residual stresses in Pb(Zr0.52Ti0.48)O3 thin films deposited by metal organic decomposition

Abstract Pb(Zr 0.52 Ti 0.48 )O 3 (PZT) ferroelectric thin films were prepared by metal organic decomposition (MOD). The residual stress in the thin film was characterized by the X-ray diffraction. The indentation fracture method including the surface crack model and half-penny crack model was developed to analyze residual stress in the thin film.

Use of nanomechanical fracture-testing for determining the interfacial adhesion of PZT ferroelectric thin films

Abstract The nano-indentation and nano-scratch fracture of Pb(Ti 0.48 Zr 0.52 )O 3 (PZT) ferroelectric thin films deposited by solution–gelatin chemistry (sol–gel) were investigated using a three-sided and conical indenter, respectively. The interfacial adhesion property of thin films was characterized by the critical strain energy release rate in the nano-mechanical fracture test. The interfacial adhesion of PZT thin films assessed by nano-indentation and nano-scratch fracture models are in good agreement. For PZT ferroelectric thin films with thickness 350 nm, the interfacial adhesion was found to be 0.921–35.468 J/m 2 . The averaged elastic modulus and indentation hardness are 120.95 and 13 GPa, respectively.

Phase equilibria of the Al–Ni–Zn system at 340°C

Abstract The phase equilibria at 340°C of the Al – Ni – Zn system were investigated by combining the diffusion couple technique with the equilibrated alloys method. The samples were examined by means of optical microscopy, X-ray diffraction, scanning electron microscopy, and electron probe microanalysis. Two ternary compounds (1 and 2) were found to exist at 340°C. The solubilities of Zn in AlNi, Al3Ni2 and Al3Ni were determined to be about 20, 2 and 1 at.% Zn, respectively. The solubilities of Al in β1-NiZn and in were measured to be about 11.5 and 1 at.% Al, respectively. The solubilities of Zn in both AlNi3 and Al3Ni5 are below 1 at.% Zn.