Photostriction is the non-thermal strain experienced by a material under illumination. Despite the intense scrutiny for its potential application in the control of magnetic layers through a ferroelectric substrate [1] or the generation of ultra-fast giant shear strain [2], it has so far been considered only very scarcely from a theoretical point of view. Here, we employ the first-principles ΔSCF method to model the photostriction phenomenon in various classical ferroelectric materials such as barium titanate, lead titanate, as well as the multiferroic bismuth ferrite [3]. This simple method reveals striking features common to all these ferroelectric, namely photostriction arises from the polarization relaxation caused by photo-induced carriers in the conduction and valence bands, resulting in a photo-induced strain mediated by the converse piezoelectric effect. Advances in the methodology, to take into account the polarization of light for instance, are also presented.
References
[1] Iurchuk, V., et al. Physical Review Letters 117, 107403 (2016).
[2] Lejman, M. et al., Nature Communications 5, 4301 (2014).
[3] C. Paillard, B. Xu, B. Dkhil, G. Geneste and L. Bellaiche, Physical Review Letters 116, 247401 (2016).