The MRSEC’s sustainability initiative for research labs expanded in its second year to 29 labs across Penn State University Park and six branch campuses. Over 400 researchers have been involved thus far. Labs completing My Green Lab certification can be paired with one of 17 undergraduate Sustainable Lab Ambassadors who apply their sustainability training to the lab setting through engaged scholarship.
An IRG1 team employed molecular beam epitaxy to synthesize heterostructures stacking a ferromagnetic topological insulator with a quantum anomalous Hall state, Cr-doped (Bi, Sb)2Te3, and an antiferromagnetic iron chalcogenide, FeTe, with an atomically sharp interface. An unexpected phenomenon emerges: interface-induced superconductivity.
Quantum materials have the potential to revolutionize technologies ranging from sensing to telecommunication and computation. However, advancement has been limited by the development of topological and Dirac materials. IRG2 researchers demonstrated a novel and widely applicable strategy to engineer relativistic electron states to develop such materials through a high-entropy approach.
Hydrogels are hydrated three-dimensional networksof hydrophilic polymers that are commonly used in the biomedical industry due to their mechanical and structural tunability, biocompatibility, and similar water content to biological tissues.
Block copolymers, with their complex morphologies, are widely used in many applications. A grand challenge associated with these materials is accelerating their design and discovery.
A team from IRG-1, working with collaborators at Argonne National Laboratory and the University of Utah, have demonstrated continuous room-temperature electrical tuning of the thermal conductivity of La0.5Sr0.5CoO3-d by a factor of more than five (a record for a single-step process) via ion-gel gating. Application of a gate voltage in these devices drives a transformation from a metallic perovskite phase to an insulating brownmillerite phase via the formation and migration of oxygen vacancies, realizing the record range of measured thermal conductivities.
Soft materials known as molecular bottlebrush block polymers comprise a polymer backbone with densely grafted polymer side chains. These materials have attracted much attention for their ability to self-assemble into ordered structures with relatively large periodicities (over 50 nm), which are rarely achieved with simpler linear polymers. However, only self-assembly into lamellar and cylindrical phases has been reported in diblock bottlebrush materials.
Rather than the typical approach of exfoliating and peeling off individual atomic layers to make a 2D material, the researchers grew the 2D material inside of another matrix. The work has dubbed this new class of materials "endotaxial" from the Greek roots "endo", meaning within, and "taxis", meaning in an ordered manner.
This article studies the reversible structure and mechanical properties of a biological dynamic polymer network. This biological material based on structural protein polymers has a glass transition at 35 °C, causing a reversible thermomechanical transition and a change in modulus spanning several orders of magnitudes.
The Cr2+-based compounds, A2CrX4, where A = M+ (e.g., K+, Cs+, Rb+) or RNH3+ (e.g., MeNH3+) and X = Cl-, Br-, are an underexplored family of lead-free layered metal-halide perovskites. These compounds attracted a great deal of interest in the 1970s and 1980s after their "transparent ferromagnetism" was discovered, but they have received virtually no attention since, perhaps because they are extremely unstable in air. Further investigation into their chemistry and properties is warranted.
