Semester of Graduation
Spring 2026
Degree Type
Thesis
Degree Name
Master of Science in Chemical Sciences
Department
Department of Chemistry & Biochemistry
Committee Chair/First Advisor
Dr. Madalynn Marshall
Second Advisor
Dr. Chetan Dhital
Third Advisor
Dr. Bharat Baruah
Abstract
Magnetic topological semimetals are an exciting class of quantum materials. In these systems, the electronic wavefunction and the coupled magnetic spin configuration are strongly influenced by the topology of the compound. The Kagome lattice is a prototypical geometrically frustrated system that provides an ideal platform for investigating candidate topological semimetals due to the unique interplay of geometric frustration, spin–orbit coupling, and strong correlations. Recently, the REAgGe (RE = rare earth) family of materials has gained attention. These compounds crystallize in the non-centrosymmetric P-62m space group and host a distorted Kagome lattice in the network of rare-earth ions. Here, we utilize chemical pressure and probe with an external magnetic field to tune the Kagome lattice distortion and spin configurations, and in turn the nontrivial topological states. We have successfully synthesized Si-doped single-crystalline REAgGe materials, as determined by X-ray diffraction and SEM-EDX. The partial substitution of the smaller Si atoms for the larger Ge atoms creates a positive chemical pressure effect, reducing the lattice dimensions. The magnetization data reveal a potential influence of the chemical pressure effect on the metamagnetic states in these materials. These results will ultimately lead to a better understanding of the interplay between magnetism and topology.
Comments
This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0025735.