Microstructure and properties of polycrystalline PZT films obtained by RF magnetron sputtering with fine variation of the composition near morphotropic phase boundary

The lead zirconate titanate (PZT) thin film was deposited on platinized silicon wafer substrate by the rf magnetron sputtering method. In order to investigate the effect of cooling ambient, oxygen partial pressure was controlled during cooling PZT films. The PZT films cooled at lower oxygen partial pressure had perovskite phase and pyrochlore phase in both as-grown and postannealed films, but in the PZT films cooled at higher oxygen partial pressure, pyrochlore phases were not detected by XRD. As the oxygen partial pressure became lower during cooling, the capacitors had low values of remanent polarization and coercive field for as-grown films. The PZT capacitor with such a low value was recovered by postannealing in air, but its electrical properties had the same tendency before and after annealing. Microstructure was also affected by cooling ambient. Higher oxygen partial pressure on cooling reduced the number of very fine grains, and enhanced uniform grain distribution. Fatigue characteristics were also enhanced by cooling at higher oxygen partial pressure. However, the imprint was negligible irrespective of oxygen partial pressure upon cooling. The cooling procedure at higher oxygen ambients is believed to reduce the amounts of nonferroelectric second phases and oxygen vacancies. We find that oxygen partial pressure during cooling is a considerable process parameter. Therefore, care should be taken in treating the parameter after depositing films.

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Ferroelectric Properties of Pb(Zr,Ti)O3 Thin Film Capacitors Made by RF Magnetron Sputtering and Heat-Treated by the Bottom Electrode Crystallization Method

Materials Science Forum ◽

10.4028/www.scientific.net/msf.514-516.1348 ◽

2006 ◽

Vol 514-516 ◽

pp. 1348-1352

Author(s):

Andréi I. Mardare ◽

Cezarina C. Mardare ◽

Raluca Savu

Keyword(s):

Thin Film ◽

Magnetron Sputtering ◽

Bottom Electrode ◽

Ferroelectric Properties ◽

Electrical Contact ◽

Rf Magnetron Sputtering ◽

Electrical Contacts ◽

Sem Images ◽

Heat Treated ◽

Pzt Films

The bottom electrode crystallization (BEC) method was applied to the crystallization of Pb(Zr,Ti)O3 (PZT) thin films deposited by RF magnetron sputtering on Pt/Ti/SiO2/Si substrates. Using a proportional-integral-differential controller, the current flowing in the Pt/Ti films provided accurately controlled Joule heating for the crystallization of the PZT films. The temperature uniformity of the heat treatments was investigated by measuring the ferroelectric properties of PZT. Platinum and tungsten wires were alternatively used as electrical contacts. Scanning electron microscopy (SEM) images were used to inspect the electrical contact regions between the platinum films and different contact wires. The PZT films showed higher remanent polarizations and lower leakage currents near the electrical contacts when Pt wires were used; the ferroelectric properties were more uniform on the PZT films heat-treated with W contact wires. The BEC method can successfully replace the more conventional means for thin film crystallization, having the advantage of being a very precise, low cost and low power consumption technique.

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Preparation and characterisation of PZT films by RF-magnetron sputtering

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2011.03.021 ◽

2011 ◽

Vol 509 (21) ◽

pp. 6242-6246 ◽

Cited By ~ 16

Author(s):

Raluca Frunza ◽

Dan Ricinschi ◽

Felicia Gheorghiu ◽

Radu Apetrei ◽

Dumitru Luca ◽

...

Keyword(s):

Magnetron Sputtering ◽

Rf Magnetron Sputtering ◽

Pzt Films

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Piezoelectric effect in epitaxial PbZr1−xTixO3 thin films near morphotropic phase boundary region

Journal of Materials Research ◽

10.1557/jmr.2005.0129 ◽

2005 ◽

Vol 20 (4) ◽

pp. 787-790 ◽

Cited By ~ 7

Author(s):

Yong Kwan Kim ◽

Sang Sub Kim ◽

Bongki Lee ◽

Hyunjung Shin ◽

Sunggi Baik

Keyword(s):

Thin Films ◽

Phase Boundary ◽

Morphotropic Phase Boundary ◽

Volume Fraction ◽

Scanning Force Microscopy ◽

Boundary Region ◽

Structural Instability ◽

Piezoelectric Response ◽

Storage Devices ◽

Pzt Films

The relationship between crystal structure and piezo-response was investigated in epitaxially grown PbZr1−xTixO3 (PZT) thin films on Pt(001)/MgO(001) with a thin PbTiO3 interlayer. Insertion of the interlayer resulted in significant relaxation ofthe strain that could be developed in the course of deposition of the PZT films, consequently leading us to single out only the effect of composition. Composition of the morphotropic phase boundary (MPB), at which tetragonal and rhombohedral phases are mixed with the same volume fraction, was found to be ∼0.55 in Ti/(Zr + Ti) ratio in our films, which is close to the value for bulk polycrystalline PZT (∼0.50). The piezoelectric response peaks were two times higher in the MPB regime than in the single phase regime due to structural instability caused by the coexistence of two phases. The results indicate that epitaxial PZT films having the MPB composition are advantageous over those of other compositions for nano-storage devices based on scanning force microscopy.

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Study of the Transverse Piezoelectric Coefficient of Pb(Zr,Ti)O3 Thin Films as a Function of Texture and Composition

MRS Proceedings ◽

10.1557/proc-596-535 ◽

1999 ◽

Vol 596 ◽

Cited By ~ 12

Author(s):

A. Seifert ◽

N. Ledermann ◽

S. Hiboux ◽

P. Muralt

Keyword(s):

Thin Films ◽

Phase Boundary ◽

Morphotropic Phase Boundary ◽

Piezoelectric Coefficient ◽

Sol Gel ◽

Pzt Thin Films ◽

Best Value ◽

Pzt Films ◽

Optimal Values

AbstractThe effective transverse piezoelectric coefficient was measured on 1 μm thick sol-gel processed Pb(Zr,Ti)O3 (PZT) thin films as a function of texture and composition. Optimal values were obtained with PZT films of {100} texture near the morphotropic phase boundary (53/47). The best value amounted to -12 C/m2

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Effect of Thickness and Annealing Temperature on the Properties of PZT Films at Morphotropic Phase Boundary Composition Prepared by Sol-Gel Spin-On Technique

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.895.17 ◽

2014 ◽

Vol 895 ◽

pp. 17-20

Author(s):

Jegatheesan Periyannan ◽

Muneewaran Muniyandi ◽

Giridharan Nambi Venkatesan

Keyword(s):

Phase Boundary ◽

Morphotropic Phase Boundary ◽

Sol Gel ◽

Preferential Orientation ◽

Morphotropic Phase Boundary Composition ◽

Si Substrates ◽

Boundary Composition ◽

Phase Boundary Composition ◽

Pzt Films ◽

Degree Of Crystallization

Pb (ZrxTi1-x)O3 films at morphotropic phase boundary composition (x=0.52) were deposited on Pt/Ti/SiO2/Si substrates by sol-gel spin on technique. Thickness of the films were varied up to 1μm by step-by-step crystallization process and annealed at 500, 600 and 700 °C. Films annealed at 500 °C had poor degree of crystallization for all the thicknesses while 600 and 700 °C annealed films were found to be well crystallized with a (111) preferential orientation. Also an enhanced degree of preferential orientation was observed on the films annealed at 600 °C compared to films annealed at 700 °C. Room temperature dielectric measurements showed higher dielectric constant values for the films annealed at 600 °C compared to films annealed at 700 °C. The remnant polarization (Pr) and coercive field (Ec) at an applied field of 160 kV/cm depicted that 600 °C annealed films had a higher Pr and lower Ec values compared with the 700 °C annealed films attributed to the higher degree of preferential orientation.

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