About this Abstract |
Meeting |
2021 TMS Annual Meeting & Exhibition
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Symposium
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Mechanical Response of Materials Investigated through Novel In-situ Experiments and Modeling
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Presentation Title |
Size Effects in Barium Titanate |
Author(s) |
Nidhin George Mathews, Ashish Kumar Saxena, Christoph Kirchlechner, N Venkataramani, Gerhard Dehm, Balila Nagamani Jaya |
On-Site Speaker (Planned) |
Nidhin George Mathews |
Abstract Scope |
Barium Titanate (BTO) is a widely accepted lead-free piezoelectric ceramic used at micron length scales and in thin film forms in applications. Our micropillar compression studies on single crystal BTO show that the elastic limit (σe) increases by 400% at sub-micron length scales. The strain accommodation mechanism at smaller length scales is by plastic flow, with size exponent of 0.96 ± 0.09. These results are then extended to understand the behaviour of BTO thin films. From microcantilever fracture measurements, it is seen that single crystal possess 45% higher KIC than the bulk while polycrystalline film has 60% lower KIC due to the weak inter-columnar boundaries. The miniaturized compression and fracture tests provide the requisite benchmarking but require expensive micromachining. This is replaced by nanoindentation combined with finite element modelling as a high throughput method to study the effect of film thickness, microstructure and residual stress on the mechanical behaviour of BTO thin films. |
Proceedings Inclusion? |
Planned: |
Keywords |
Mechanical Properties, Thin Films and Interfaces, |