Our article "Oxide Membranes from Bulk Micro-Machining of SrTiO₃ Substrates" has been accepted on Advanced Science !

abstract: Suspended micro-structures made of epitaxial complex oxides rely on surface micro-machining processes based on sacrificial layers. These processes prevent to physically access the microstructures from both sides, as substantial part of the substrate is not removed. In this work, a bulk micromachining protocol is developed for a commonly used substrate employed in oxide thin films deposition. Suspended oxide thin film devices are realized by fabricating pass-through holes across SrTiO3(100) or SrTiO3(110) substrates. Careful calibration of anisotropic etching rates allows controlling the final geometry of the aperture in the substrate in a predictable way. As demonstrators of possible device geometries, clamped membranes and trampolines realized from deposited thin films of (La,Sr)MnO3, a conductive magnetic oxide, and a suspended trampoline resonator carved from the SrTiO3 substrate itself are presented. Reported protocols can be readily applied to a broad variety of other complex oxides so to extend the use of membranes technology beyond those of commercially available silicon compounds.

This year the results of the OXiNEMS project have been presented at the 30th International workshop on Oxide Electronics (iWOE30) held in Darmstadt (Germany) from 29 September to 2 October 2024.

Here the list of our presentations:

• "Bulk micro-machining of SrTiO3 substrates for device applications" (Poster by Nicola Manca)
• "Strain, Young’s modulus, and structural transition of EuTiO3 thin films probed by micro-mechanical methods" (Poster by Daniele Marré)
• "(La0.7,Sr0.3)MnO3 trampoline resonators for magnetometers and IR bolometers" (Poster by Luca Pellegrino)
• …and one oral contribution “Integration of High-Tc Superconductors and High Q-factor Mechanical Resonators in LaAlO₃ Suspended Micro-Bridges” given by Nicola Manca

Nicola Manca was awarded with “The Oxide Electronics Prize for Excellence in Research” for “his groundbreaking research on microelectromechanical devices with epitaxial oxides”.

The prize was given at the 30th International workshop on Oxide Electronics (iWOE30) held in Darmstadt (Germany) from 29 September to 2 October 2024.

Many congratulations to Nicola!

Our article “Integration of High-Tc Superconductors with High-Q-Factor Oxide Mechanical Resonators” has been accepted for publication on Advanced Functional Materials."

We realized a micro-mechanical resonator showing both high mechanical Q-factor and superconductivity at 77 K. This result was achieved by integrating a high-Tc superconductor YBa2Cu3O7 (YBCO) with a high Q-factor micro-bridge resonators made of single-crystal LaAlO3 (LAO) thin films. Bare LAO resonators are tensile strained, with a stress of about 350 MPa, and show a mechanical Q-factor above 200k at room temperature. Additionally, they have low surface roughness. A YBCO film was then grown ex-situ by pulse laser deposition on top of the suspended bridges. Final devices show zero resistance below 78 K and mechanical properties similar to those of bare LAO ones. These results open new possibilities towards the development of advanced transducers, such as bolometers or magnetic field detectors, as well as experiments in solid state physics, material science, and quantum opto-mechanics.

For further readings:

N. Manca, A. Kalaboukhov, A. E. Plaza, L. Cichetto Jr., E. Wahlberg, E. Bellingeri, F. Bisio, F. Lombardi, D. Marré, L. Pellegrino, “Integration of High-Tc Superconductors with High-Q-Factor Oxide Mechanical Resonators” Adv. Funct. Mater. 2024, 2403155.