Doctor of Philosophy (PhD)



Document Type



Our primary research goals are to synthesize, characterize, and study the structure, dimensionality, and physical properties of new highly correlated electron materials. Intermetallic lanthanide and oxide phases are of great interest due to their fascinating array of structural features and physical property phenomena, such as heavy fermion behavior, superconductivity, and magnetism. The crystal growth, structure, and physical properties of several different classes of materials, such as the Ln-M-Ga (Ln = La, Ce, Pr, M = Ni, Pd), Yb5Pt9, and R2Ir2O7 (R = Pr, Eu) compounds, will be highlighted within. The Ln-M-Ga phases allow us to examine the influence of the lanthanide environments, dimensionality and layering on the magnetic and transport properties in these compounds. For example, CePdGa6 is a heavy fermion with ã ~ 230 mJ mol-1 K-2 and exhibits an anisotropic magnetism with TN ~ 5.5 K. The structurally related compound, Ce2PdGa10, also shows enhanced mass behavior (ã ~ 220 mJ/mol- K2), exhibits paramagnetic behavior down to 2 K, and has a large positive MR > 200 % at 2 K and 9 T. Also bearing a striking resemblance to the CePdGa6 phase, Ce2PdGa12 is an antiferromagnetic heavy fermion with ã ~ 170 mJ mol-1 K-2 and a magnetic transition at TN ~ 11 K. The crystal structures and physical properties of several new Ln2NiGa10 (Ln = La, Ce, Pr) and Ln2NiGa12 (Ln = La, Ce, Pr) compounds will also be discussed and compared to determine the role of the lanthanide and transition metal environments. The oxide pyrochlores, R2Ir2O7 (R = Pr, Eu), which show geometrically frustrated magnetism, may also offer insight into the structure-property relationships in three dimensional materials.



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Committee Chair

Julia Y. Chan

Included in

Chemistry Commons