Phase transformations in rapid thermal processed lead zirconate titanate

1995 ◽  
Vol 10 (12) ◽  
pp. 3149-3159 ◽  
Author(s):  
Ellen M. Griswold ◽  
L. Weaver ◽  
M. Sayer ◽  
I.D. Calder
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Lead Zirconate ◽  
Grain Structure ◽  
Avrami Model ◽  
Pzt Thin Films ◽  
Zirconate Titanate

The crystallization kinetics of the pyrochlore to perovskite phase transformation in lead zirconate titanate (PZT) thin films have been analyzed using rapid thermal processing (RTP). Sol-gel PZT thin films, fabricated on platinum electrodes, were annealed at 550 °C to 650 °C with hold times ranging from 1 s to 5 min. Glancing angle x-ray diffraction (XRD) was used for depth profiling to identify the location of phases in the films. Transmission electron microscopy (TEM) provided information on grain structure, nucleation, and growth. The phase information was correlated to the ferroelectric and dielectric properties. The perovskite phase nucleated in the pyrochlore phase throughout the film thickness, and at 650 °C the transformation was complete in 15 s. Fast growing (100) PZT nucleated at the platinum and consumed a small-grained matrix until a columnar structure was obtained. A ramp rate of 100 °C/s was sufficiently fast to prevent transformation during heating and allowed the direct application of an Avrami model for transformation kinetics. An activation energy of 610 kJ/mol was determined.

Reactive ion etching of sol-gel deposited lead zirconate titanate (pzt) thin films in sf6 plasmas

2001 ◽  
Vol 37 (1-4) ◽  
pp. 67-74 ◽  
Author(s):  
George McLane ◽  
Ronald Polcawich ◽  
Jeffrey Pulskamp ◽  
Brett Piekarski ◽  
Madan Dubey ◽  
...  
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Sol Gel ◽  
Reactive Ion Etching ◽  
Lead Zirconate ◽  
Ion Etching ◽  
Pzt Thin Films ◽  
Zirconate Titanate

Kinetics of formation of the pyrochlore and perovskite phases in sol-gel derived lead zirconate titanate powder

1998 ◽  
Vol 13 (8) ◽  
pp. 2170-2173 ◽  
Author(s):  
V. S. Tiwari ◽  
Arun Kumar ◽  
V. K. Wadhawan ◽  
Dhananjai Pandey
Keyword(s):  
Lead Zirconate Titanate ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Lead Zirconate ◽  
Oxygen Stoichiometry ◽  
X Ray ◽  
Zirconate Titanate ◽  
Kinetics Of Formation ◽  
Kinetics Of

Lead zirconate titanate (PZT) powder is prepared by the sol-gel method. The formation of pyrochlore and perovskite phases is investigated by high temperature x-ray diffraction (XRD) and thermal analysis techniques. The pyrochlore phase first appears in x-ray amorphous form, and then gets converted to crystalline state on annealing in air. We show that vacuum annealing of the pyrolyzed amorphous PZT gel suppresses the formation of the crystalline pyrochlore phase. This, in turn, enhances the kinetics of conversion of pyrochlore to perovskite, such that a pyrochlore-free perovskite phase can be obtained by annealing at about 500 °C. On the other hand, if annealing is carried out in air, a crystalline pyrochlore phase is formed, which requires annealing temperatures higher than 600 °C for transformation to the perovskite phase. These observations are explained tentatively in terms of the oxygen stoichiometry of the two phases.

Microstructural development in sol-gel derived lead zirconate titanate thin films: The role of precursor stoichiometry and processing environment

1996 ◽  
Vol 11 (8) ◽  
pp. 2076-2084 ◽  
Author(s):  
M. J. Lefevre ◽  
J. S. Speck ◽  
R. W. Schwartz ◽  
D. Dimos ◽  
S. J. Lockwood
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Lead Zirconate Titanate ◽  
Single Phase ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Lead Zirconate ◽  
Microstructural Development ◽  
Zirconate Titanate

The role of precursor stoichiometry and local firing environment on the microstructural development of sol-gel derived lead zirconate titanate (PZT) thin films was investigated. Typically, excess Pb is added to films to compensate for PbO volatilization during heat treatment. Here, it is shown that the use of stoichiometric precursors with either a PbO atmosphere powder or a PbO overcoat during the crystallization heat treatment is an attractive and viable alternative method for control of film stoichiometry. Using these approaches, we have fabricated single phase perovskite thin films with microstructures and electrical properties (Pr ∼ 36 μC/cm2 and Ec ∼ 45 kV /cm) comparable to those of films using optimized solution chemistries and excess Pb additions. The potential advantage of increasing PbO partial pressure, or activity, during firing versus excess Pb additions is discussed from the standpoint of a proposed crystallization scenario based on the kinetic competition between Pb loss and the nucleation and growth rates of the perovskite phase.

Low temperature perovskite formation of lead zirconate titanate thin films by a seeding process

1993 ◽  
Vol 8 (2) ◽  
pp. 339-344 ◽  
Author(s):  
Chi Kong Kwok ◽  
Seshu B. Desu
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Lead Zirconate Titanate ◽  
Transformation Temperature ◽  
Perovskite Phase ◽  
Lead Zirconate ◽  
Grain Structure ◽  
Phase Transformation Temperature ◽  
Seeding Layer ◽  
Zirconate Titanate

A two-step seeding process has been developed to lower the transformation temperature and modify the grain structure of ferroelectric lead zirconate titanate (PZT) thin films with high Zr/Ti ratio. Previous study has shown that nucleation is the rate-limiting step for the perovskite formation. Therefore, any process that enhances the kinetics of nucleation is likely to decrease the transformation temperature. In this process, a very thin (45 nm) seeding layer of PbTiO3, which has a low effective activation energy for perovskite formation, was used to provide nucleation sites needed for the low temperature perovskite formation. In this study, we have shown that the pyrochlore-to-perovskite phase transformation temperature of PbZrxTi1−xO3 films of high Zr/Ti ratio (e.g., x = 53/47) can be lowered by as much as 100 °C. The grain size of these films can also be substantially modified by this two-step approach.

A Study on the Microstructure of Preferred Orientation of Lead Zirconate Titanate (PZT) Thin Films

1997 ◽  
Vol 12 (4) ◽  
pp. 1043-1047 ◽  
Author(s):  
Chang Jung Kim ◽  
Dae Sung Yoon ◽  
Joon Sung Lee ◽  
Chaun Gi Choi ◽  
Kwangsoo No
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Sol Gel ◽  
Lead Zirconate ◽  
Preferred Orientation ◽  
X Ray Diffraction ◽  
Pzt Thin Films ◽  
X Ray ◽  
Zirconate Titanate

The lead zirconate titanate (PZT) thin films were fabricated using sol-gel spin coating onto Pt/Ti/glass substrates. Effects of the holding time for pyrolysis and the coating cycle on the preferred orientation of the PZT thin films were studied. The films were fabricated with different coating cycles (3, 5, 7, 9, 11), dried at 330 °C for different holding times (5, 30, 60 min), and then annealed at the same temperature of 650 °C using rapid thermal annealing (RTA). The preferred orientations of the films were investigated using x-ray diffraction and glancing angle x-ray diffraction. The microstructure and the selected area diffraction pattern of the PZT thin films were also investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively.

Effect of Pb Excess Content on Microstructure and Electrical Properties of Sol Gel Derived PZT Thin Films

1999 ◽  
Vol 596 ◽  
Author(s):  
Zhan-jie Wang ◽  
Ryutaro Maeda ◽  
Kaoru Kikuchi
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Lead Zirconate ◽  
Pzt Thin Films ◽  
Starting Solution ◽  
Pzt Films

AbstractLead zirconate titanate (PZT) thin films were fabricated by a three-step heat-treatment process which involves the addition of -10, 0 and 10 mol% excess Pb to the starting solution and spin coating onto Pt/Ti/SiO2/Si substrates. Crystalline phases as well as preferred orientations in PZT films were investigated by X-ray diffraction analysis (XRD). The microstructure and composition of the films were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron probe microanalysis (EPMA), respectively. The well-crystallized perovskite phase and the (100) preferred orientation were obtained by adding 10% excess Pb to the starting solution. It was found that PZT films to which 10% excess Pb was added had better electric properties. The remanent polarization and the coercive field of this film were 34.8 μC/cm2 and 41.7 kV/cm, while the dielectric constant and loss values measured at 1 kHz were approximately 1600 and 0.04, respectively. Dielectric and ferroelectric properties were correlated to the microstructure of the films.

Early Stages of Crystallization of Sol−Gel-Derived Lead Zirconate Titanate Thin Films

2003 ◽  
Vol 15 (5) ◽  
pp. 1147-1155 ◽  
Author(s):  
A. Wu ◽  
P. M. Vilarinho ◽  
I. Reaney ◽  
I. M. Miranda Salvado
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Sol Gel ◽  
Lead Zirconate ◽  
Early Stages ◽  
Zirconate Titanate
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