Investigation of the Emerging Magnetic Behavior in a Breathing Spinel Material
Disciplines
Inorganic Chemistry
Abstract (300 words maximum)
The Pyrochlore lattice, a corner-sharing tetrahedral network, is a prime candidate for geometric frustration in three dimensions. This lattice appears in various materials, including spinels with the general formula AM₂X₄ (A = alkali, alkaline earth metals, heavier 3d transition metals, Ge, Cd, Hg; M = transition and post-transition metals; X = group 16 elements). Introducing two different-sized cations at the A site forms the breathing pyrochlore lattice, observed in materials with the general formula AA'Cr₄X₈. Partial A-site substitution creates two inequivalent tetrahedra with bond distances d, d' and a breathing ratio d′/d, leading to two inequivalent nearest-neighbor magnetic exchange interactions J, J'. These additional degrees of freedom allow the tunability of frustration within the lattice, giving rise to exotic magnetic states.
This talk will explore the chemical tuning effects of A and A' sites on the structure, breathing ratio, and magnetic behavior in the breathing spinel CuA'Cr₄Se₈ family. CuAlCr₄Se₈ exhibits a highly frustrated magnetic nature with complex order and a freezing temperature (Tf) of approximately 13 K. Its strong frustration, exclusion of rare-earth elements, and low transition temperatures make breathing spinels promising magnetocaloric candidates for low-temperature applications. The complex magnetic order in this family provides a pathway to achieve a large magnetocaloric effect (MCE) via highly frustrated magnetism. Using an indirect measurement approach, we have assessed the MCE potential of the CuA'Cr₄Se₈ family.
Academic department under which the project should be listed
CSM - Chemistry and Biochemistry
Primary Investigator (PI) Name
Madalynn Marshall
Investigation of the Emerging Magnetic Behavior in a Breathing Spinel Material
The Pyrochlore lattice, a corner-sharing tetrahedral network, is a prime candidate for geometric frustration in three dimensions. This lattice appears in various materials, including spinels with the general formula AM₂X₄ (A = alkali, alkaline earth metals, heavier 3d transition metals, Ge, Cd, Hg; M = transition and post-transition metals; X = group 16 elements). Introducing two different-sized cations at the A site forms the breathing pyrochlore lattice, observed in materials with the general formula AA'Cr₄X₈. Partial A-site substitution creates two inequivalent tetrahedra with bond distances d, d' and a breathing ratio d′/d, leading to two inequivalent nearest-neighbor magnetic exchange interactions J, J'. These additional degrees of freedom allow the tunability of frustration within the lattice, giving rise to exotic magnetic states.
This talk will explore the chemical tuning effects of A and A' sites on the structure, breathing ratio, and magnetic behavior in the breathing spinel CuA'Cr₄Se₈ family. CuAlCr₄Se₈ exhibits a highly frustrated magnetic nature with complex order and a freezing temperature (Tf) of approximately 13 K. Its strong frustration, exclusion of rare-earth elements, and low transition temperatures make breathing spinels promising magnetocaloric candidates for low-temperature applications. The complex magnetic order in this family provides a pathway to achieve a large magnetocaloric effect (MCE) via highly frustrated magnetism. Using an indirect measurement approach, we have assessed the MCE potential of the CuA'Cr₄Se₈ family.
