STRAIN IMAGING OF A PB(ZR,TI)O3 THIN FILM

Strain‐imaging observation of a lead‐zirconate‐titanate film using a tunneling acoustic microscope (TAM) is described. This method detects fine strains in the piezoelectric film generated by the tip voltage and, therefore, measures and images the piezoelectric properties of the sample. The strains are detected either as a surface displacement of the sample by the feedback loop to keep the tip‐to‐sample spacing constant, or as a vibration generated by an alternating current tip voltage by the acoustic transducer in the TAM. Microscopic properties of a 70‐nm‐thick Pb(Zr0.5Ti0.5)O3 film grown by sputtering were investigated, and ferroelectricity was observed by applying voltages to areas of a couple of tens of nanometers in diameter. Local polarization control and its related space charge effect induced by the tip voltage are also shown.