CAREER: Pressure-directed synthesis of anisotropic lanthanide materials

Non-technical Summary:

The discovery of new materials is essential to bridging the gap between current and targeted information transport and storage technologies. Recently, a promising class of materials with layered chemical motifs that behave as magnets even upon the reduction of bulk solids to single layer materials has been realized, but such systems remain difficult to rationally design.

One route to expanding this class of materials is to use high pressures (equivalent to the interiors of some planets) to distort known structures or enable entirely new reactions that yield layered motifs that can persist once the materials are returned to ambient pressures. With support from the Solid State and Materials Chemistry Program in NSF’s Division of Materials Research, researchers at Texas A&M University elucidate the design principles of such materials by using tunable pressures to incrementally change the interactions between atoms until chemical reactions are observed.

The experimental effort is supported by computational predictions, and the researchers also measure the material’s properties as a function of pressure. Enhancing these efforts is also significant investment in solid-state chemistry outreach. Targeting broad involvement across learning communities and educational stages, the principal investigator and her team design and organize workshops that connect materials chemistry with everyday examples to expand definitions of what it means to be a solid-state chemist.

Technical Summary:

Materials in which magnetism persists to the monolayer limit are a notable discovery of the last decade, with potentially transformative applications as novel information processing platforms. Such magnetic order arises from the convolution of spin and orbital degrees of freedom in the form of spin-orbit coupling (SOC) which is inherent to high-Z elements (where Z = atomic number).

Lanthanide elements in particular, with their potential maximal amounts of spin degrees of freedom and large amounts of spin-orbit coupling, embody this potential. Yet, the intersection of their electronic anisotropy and structural anisotropy remains underexplored and significant gaps persist regarding synthetic tools for the rational design of anisotropic structures in lanthanide materials.

With support from the Solid State and Materials Chemistry Program in NSF’s Division of Materials Research, researchers at Texas A&M University investigate the use of high-pressure techniques to access orbital configurations implicated in structural anisotropy, targeting new examples of layered lanthanide materials beyond ambiently accessible systems. The project makes use of a combined synthetic, computational and spectroscopic approach to reveal design criteria for controlled magnetic behavior.

Simultaneously, the principal investigator and her team enable broad involvement across learning communities and educational stages by developing and sharing a materials chemistry of food curriculum for K–12 learners as well as implementing an X-ray crystallography workshop to serve undergraduate and graduate students across East Texas.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.