Phys.org March 18, 2024
Freestanding oxide membranes have a variety of interesting applications, but pulling these materials off the substrate after synthesis can be challenging. An international team of researchers (China, Austria) has developed a water-soluble sacrificial layer, “super-tetragonal” Sr4Al2O7 (SAOT). The low-symmetric crystal structure enabled a superior capability to sustain epitaxial strain, allowing for broad tunability in lattice constants resulting in structural coherency and defect-free interface in perovskite ABO3/SAOT heterostructures effectively restraining crack formation during the water release of freestanding oxide membranes. For a variety of nonferroelectric oxide membranes, the crack-free areas can span up to a millimeter in scale. According to the researchers SAOT is a versatile and feasible sacrificial layer for producing high-quality freestanding oxide membranes… read more. TECHNICAL ARTICLE
Schematic illustration of water-assisted exfoliation of freestanding oxide membranes from SAOC and SAOT sacrificial layers. Credit: Prof. Wu Wenbing’s team.