Ferroelectronics Lab

Understanding and utilizing non-volatile properties of materials

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New Publication! “Chemically-Disordered Transparent Conductive Perovskites With High Crystalline Fidelity”

July 18, 2025 By Avery-Ryan Ansbro

Abstract: This manuscript presents a working model linking chemical disorder and transport properties in correlated-electron perovskites with high-entropy formulations and a framework to actively design them. This work demonstrates this new learning in epitaxial Srx(Ti,Cr,Nb,Mo,W)O3 thin films that exhibit exceptional crystalline fidelity despite a diverse chemical formulation where most B-site species are highly misfit with respect to valence and radius. X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy confirm a unique combination of chemical disorder and structural perfection in thin and thick epitaxial layers. This combination produces an optical transparency window that surpasses that of the constituent end-members in the UV and IR, while maintaining relatively low electrical resistivity. This work addresses the computational challenges of modeling such systems and investigate short-range ordering using cluster expansion. These results showcase that unusual d-metal combinations access an expanded property design space that is predictable using end-member characteristics and their interactions– though unavailable to them– thus offering performance advances in optical, high-frequency, spintronic, and quantum devices.

Read more at Advanced Science

Filed Under: Publications Tagged With: high entropy, John T. Heron, Pat Kezer, perovskite, publications

New Publication! “Engineering antiferromagnetic magnon bands through interlayer spin pumping”

March 28, 2025 By Avery-Ryan Ansbro

Abstract: Spin pumping, a central phenomenon in spintronics used to source pure spin currents, is best understood in collinear magnetic multilayers. There is not yet a unified Landau-Lifshitz-Gilbert (LLG) theory that captures the fieldlike and dampinglike torques in a generic noncollinear magnetic multilayer. Here, we theoretically expand the LLG phenomenology to incorporate both dynamic fieldlike and dampinglike torques arising from spin pumping within noncollinear magnetic materials. We find that often overlooked dynamic fieldlike torques are capable of unveiling inversion asymmetries present in magnetic multilayers. Consequently, spin pumping can be used to lift the spectral degeneracy between various magnon modes in noncollinear antiferromagnets. We experimentally confirm this magnon-magnon interaction in a synthetic antiferromagnetic tetralayer, which has highly noncollinear magnetization configurations when under the influence of an external field. Thus, we demonstrate how spin pumping can facilitate a magnon-magnon interaction, significantly expanding how magnonic interactions can be engineered into antiferromagnets and magnetic metamaterials.

Read more at Physics Review Applied

Filed Under: Publications Tagged With: John T. Heron, magnetism, Peter Meisenheimer, publications

New Publication! “Polydopamine-Assisted Electroless Deposition of Magnetic Functional Coatings for 3D-Printed Microrobots”

January 31, 2025 By Avery-Ryan Ansbro

Abstract: Magnetic microrobots are attractive tools for operation in confined spaces due to their small size and untethered wireless operation, particularly in biomedical and environmental applications. Over years of development, many microrobot fabrication methods have been developed; however, they typically require costly specialized physical vapor deposition (PVD) vacuum instrumentation and present homogeneity and conformality coating problems (especially in complex 3D structures). Herein, a solution-based polydopamine (PDA)-assisted electroless deposition method is developed to deposit a superparamagnetic nickel thin film on microrobots. The multilayered functional film design comprises PDA as an adhesive primer and reducing agent, silver nanoclusters as catalysts, and a nickel magnetic top film, all deposited in a batch solution-based process on glass and 3D-printed polymer substrates. This multilayer magnetic coating is implemented and demonstrated in three magnetic microrobot archetypes, including arbitrarily-shaped active particles, microrollers, and helical swimming microrobots, each using distinct actuation working mechanisms. Due to the material-independent interfacial adhesive properties of PDA, this multilayer functionalization strategy can open up new magnetic microrobot fabrication schemes with a broad compatibility with materials and structures (including complex 3D-printed polymer microstructures) and without the need for and limitations of PVD coating approaches.

Read more on Advanced Intelligent Systems

Filed Under: Publications Tagged With: John T. Heron, magnetism, Microbots, organic

News

  • New Publication! “Chemically-Disordered Transparent Conductive Perovskites With High Crystalline Fidelity” July 18, 2025
  • New Publication! “Engineering antiferromagnetic magnon bands through interlayer spin pumping” March 28, 2025
  • New Publication! “Polydopamine-Assisted Electroless Deposition of Magnetic Functional Coatings for 3D-Printed Microrobots” January 31, 2025

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About

Our research is at the intersection of multiple disciplines, drawing on principles and methodologies from materials science, chemistry, physics, and electrical engineering. Our mission is to pioneer … Read More

News

New Publication! “Chemically-Disordered Transparent Conductive Perovskites With High Crystalline Fidelity”

July 18, 2025 By Avery-Ryan Ansbro

New Publication! “Engineering antiferromagnetic magnon bands through interlayer spin pumping”

March 28, 2025 By Avery-Ryan Ansbro

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Ferroelectronics Lab
Address: 2030 H.H. Dow

T: (734) 763-6914
E: jtheron@umich.edu
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