Influence of tensile vs. compressive stress on fatigue of lead zirconate titanate thin films. Issue 14 (November 2021)

• Record Type: Journal Article
• Authors: Aruchamy, Naveen; Schenk, Tony; Kovacova, Veronika; Glinsek, Sebastjan; Defay, Emmanuel; Granzow, Torsten
• Is Part Of: Journal of the European Ceramic Society. Volume 41:Issue 14(2021)
• Page Start: 6991
• Page End: 6999
• Publication Date: 2021-11
• Subjects: PZT -- Residual stress -- Ferroelectric domain walls -- Domain wall pinning; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2021.07.010
• Languages: English
• ISSNs: 0955-2219

Abstract

Highlights: A PZT film solution-deposited on fused silica is under tensile in-plane stress, on sapphire it is under compressive stress. Tensile stress favors in-plane domains with mainly 90° domain walls, compressive stress out-of-plane domains with 180° walls. Fatigue in films on fused silica with more 90° walls is gradual, caused by pinning of domain walls on existing defects. Films on sapphire fatigue rapidly after formation of defect agglomerates which pin 180° domain walls. Comparison of large and small-signal permittivity shows that fatigue drastically reduces irreversible domain wall processes. Abstract: Novel applications of ferroelectric films require a variety of different substrates, which exert different mechanical stress on the film. This raises the question of reliability of differently stressed films. This work compares the cycling-induced fatigue of the polarization hysteresis of PZT films in different stress states. A tensile stress of +270 MPa, for PZT on fused silica glass, causes gradual degradation, while degradation sets in abruptly under compressive stress of −100 MPa, for PZT on sapphire. The main fatigue mechanism is domain wall pinning on charged defects. Reversible and irreversible domain wall processes in the small- and large-signal permittivity reveal that the fatigue behavior results from a variation of the ferroelectric domain structure. Films under tensile stress contain more 90° domain walls, which get pinned continuously on isolated defects. Compressive stress creates more 180° domain walls, which require formation of defect agglomerates during a certain threshold cycle number for pinning.