• Bagri, A.; Jana, A.; Panchal, G.; Phase, D.M.; Choudhary, R.J.: Amalgamation of Photostriction, Photodomain, and Photopolarization Effects in BaTiO3 and Its Electronic Origin. ACS Applied Electronic Materials 4 (2022), p. 4438-4445

Open Access Version

Multifunctional oxides offer huge potential for technological applications, owing to their inclusive physical properties such as ferroelectric, piezoelectric, and electro-caloric properties. The natural occurrence of piezoelectricity, a tunable band gap of ferroelectrics, opens a path to study the light–material interaction, leading to photoconduction and photovoltaic effects. Such light-controlled devices yield additional advantages of weight reduction and wireless, remote-controlled functionality over the heavy electric circuitry and, hence, are projected as an alternative solution to the traditional piezoelectric-based devices. Among these materials, lead-free BaTiO3-based ferroelectric materials are a good choice for their potential applications with recently discovered light-controlled functionality. However, until now, the coupling of light with the chemistry of ferroelectricity of BaTiO3 crystals has been elusive, although the ferroelectricity and piezoelectricity are well-studied. Here, the present study reports the photostrictive effect of the order of 10–4 on the dimension of the c domains of tetragonal BaTiO3 crystals and domain reorientation at room temperature under unpolarized, coherent visible light illumination, consequently resulting in enhancement in polarization. The electronic origin of domain evolution and photostriction is explained by the light-induced modification in the Ti 3d–O 2p-hybridized orbitals. This facilitates the perspective of combining mechanical, electrical, optical, and functionalities in future generations of remote-controlled devices.