Microstructure and Properties of PZT Films with Different PbO Content-Ionic Mechanism of Built-In Fields Formation.

Nikolay Mukhin,Liubov Bakhchova,Dmitry Chigirev,Andrey Tumarkin

doi:10.3390/ma12182926

Abstract

Experimental studies were conducted on the effects of lead oxide on the microstructure and the ferroelectric properties of lead zirconate-titanate (PZT) films obtained by the method of radio frequency (RF) magnetron sputtering of a ceramic PZT target and PbO2 powder with subsequent heat treatment. It is shown that the change in ferroelectric properties of polycrystalline PZT films is attributable to their heterophase structure with impurities of lead oxide. It is also shown that, even in the original stoichiometric PZT film, under certain conditions (temperature above 580 °C, duration greater than 70 min), impurities of lead oxide may be formed. The presence of a sublayer of lead oxide leads to a denser formation of crystallization centers of the perovskite phase, resulting in a reduction of the grain size as well as the emergence of a charge on the lower interface. The formation of the perovskite structure under high-temperature annealing is accompanied by the diffusion of lead into the surface of the film. Also shown is the effect of the lead ions segregation on the formation of the self-polarized state of thin PZT films.

Highlights

Ferroelectric materials in both bulk and thin-film forms are widely used in electronics and technology
These are the results of stoichiometric properties of lead zirconate-titanate (PZT) films of relatively large thickness—around 1.5 μm—which was chosen in order to see the volumetric effects
We have studied the effect of lead oxide sublayer on PZT films and PZT-based thin-film structures properties (Figure 4)

Summary

Introduction

Ferroelectric materials in both bulk and thin-film forms are widely used in electronics and technology. PZT is interesting because it allows almost all applications of ferroelectrics to be covered due to the fact that, depending on the composition [9] and the alloying additives [10,11], it is possible to synthesize PZT with varied physical properties and material parameters over a very wide range while adapting them to the requirements of the specific practical application. Such properties are associated with high dielectric permeability and residual polarization, a large number of transition cycles, high breakdown voltage, pyroelectric and piezoelectric effects, electro-optical phenomena, photoelectricity, etc

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