2025/05/07 by Prachi Thureja, Andrew W. Nyholm, Thureja, Prachi +9
Engineering · Materials Science · Physics and Astronomy · #Applied Physics (physics.app-ph) #FOS: Physical sciences #Ferroelectric and Piezoelectric Materials #Microwave Dielectric Ceramics Synthesis #Photorefractive and Nonlinear Optics
paper · pdf · doi:10.48550/arxiv.2505.04045
openalex publication_date 2025/05/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We report a scalable approach for fabricating single-crystal barium titanate (BTO) thin films through spalling from bulk substrates. Conventional thin film growth techniques often face challenges in achieving high-quality single crystal microstructure over large areas, resulting in reduced performance in functional devices. In contrast, spalling - i.e., performing stress-induced exfoliation of bulk single crystals - enables the separation of single crystal thin films with controllable thicknesses ranging from 100 nm to 15 um and lateral dimensions up to several millimeters. Electro-optic characterization of the spalled films yields a Pockels coefficient of r33 = 55 pm/V in multi-domain regions and 160 pm/V in single-domain regions, leading to projections up to 1980 pm/V for r42 under conditions of unclamped excitation. Our results indicate that spalled BTO single-crystal thin films preserve bulk electro-optic properties and exceed the performance of commercially available thin-film lithium niobate, making them suitable for integration in advanced photonic and optoelectronic devices.