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arXiv · 1003.3353

Origin of the anomalous piezoelectric response in wurtzite Sc$_x$Al$_{1-x}$N alloys

Ferenc Tasnádi·Björn Alling·Carina Höglund·Gunilla Wingqvist·Jens Birch·Lars Hultman·Igor A. Abrikosov
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Abstract

The origin of the anomalous, 400% increase of the piezoelectric coefficient in Sc$_x$Al$_{1-x}$N alloys is revealed. Quantum mechanical calculations show that the effect is intrinsic. It comes from a strong change in the response of the internal atomic coordinates to strain and pronounced softening of C$_{33}$ elastic constant. The underlying mechanism is the flattening of the energy landscape due to a competition between the parent wurtzite and the so far experimentally unknown hexagonal phases of the alloy. Our observation provides a route for the design of materials with high piezoelectric response.

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Ferenc Tasnádi, Björn Alling, Carina Höglund, Gunilla Wingqvist, Jens Birch, Lars Hultman, Igor A. Abrikosov. 2010-03-17. Origin of the anomalous piezoelectric response in wurtzite Sc$_x$Al$_{1-x}$N alloys. https://doi.org/10.1103/physrevlett.104.137601

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