Microstructural evolution of Pb(Zr, Ti)O₃ thin films prepared by hybrid metallo-organic decomposition

Abstract

We report on the microstructural analyses of chemically prepared Pb(Zr0.53Ti0.47)O3 (PZT 53/47) films. Although several techniques were used to analyze films, transmission electron microscopy (TEM) was emphasized. Phase evolution of these films, fabricated using hybrid metallo-organic decomposition (HMD), was determined by processing films at temperatures ranging from 500 °C to 650 °C. Our films, when observed with an optical microscope, appeared to consist of two distinct phases: (1) a featureless matrix and (2) 1–2 μm diameter “rosettes”. PZT films fired at 500 °C consisted of a pyrochlore containing phase (featureless matrix) and contained no perovskite, whereas films fired at 600 °C were ferroelectric and were approximately 90% perovskite (rosettes) by volume. Our TEM analysis showed that the pyrochlore-containing phase consisted of interpenetrating nanocrystalline pyrochlore and amorphous phases, both with dimensions on the order of 5 nm. For PZT films processed at 650 °C, the perovskite phase was observed in two forms: (1) large (≍2 μm) rosette structures containing 30 nm pores and (2) dense equiaxed particles on the order of 100 nm. We propose that phase evolution—with increasing temperature of HMD PZT 53/47 films—consists of the following steps: (1) phase separation, probably occurring in solution, (2) pyrochlore crystallization, (3) heterogeneous nucleation of perovskite PZT, and (4) homogeneous nucleation of perovskite PZT.

Micropatterned lead zirconium titanate thin films

“…[30][31][32][33] Our TEM observations agreed with these findings. The perovskite phase nucleated at the filmsubstrate interface (Fig.…”

Investigation of Pt/Ti bilayer metallization on silicon for ferroelectric thin film integration

“…Detailed studies on the stability of Pt/Ti bilayer metallizations in an oxidizing ambient have scarcely been reported. Large variations in the thicknesses of Pt and Ti layers listed in Table I have been attempted [12][13][14][15][16][17][18][19][20][21][22]. Recent studies [13,14,23] on the stability of Pt/Ti bilayers in an oxidizing atmosphere pointed out a potential problem arising due to the oxidation of the intermediate Ti-bonding layer, and its diffusion into the Pt film.…”

Piezoelectric Pressure Sensor Based on Enhanced Thin-Film PZT Diaphragm Containing Nanocrystalline Powders

“…The first challenge in structural development is to form the desired perovskite crystal structure and eliminate the metastable pyrochlore (or fluorite [38]) form. On heating, pyrochlore forms at a lower temperature than does perovskite [39][40][41] and is a common alternative form for many perovskite ferroelectrics, particularly relaxor ferroelectrics. Because this pyrochlore is non-ferroelectric and has a low dielectric constant, both the ferroelectric and dielectric constant are degraded by its presence [40].…”