Synthetic Design of Cerium-Based Intermetallics
Abstract
Ce-based highly correlated systems are of interest due to Ce3+ (S=1/2) providing an ideal f-electron system to study the interplay of localized magnetic moments and conduction electrons. The growth of high-quality single crystals is of utmost importance to ensure the determination of intrinsic anisotropic properties. This dissertation presents the single crystal growth and d etailed characterization of Ce-containing intermetallics. Motivated by the search for new spintronic devices based on topological materials, the first study highlights the incorporation of Bi in the topological parent compound, CeSbTe. Sb net containing CeSbTe has been studied to show the interplay of magnetism and topology. Inserting Bi, a larger element, provides the opportunity to change the Fermi surface while preserving topologically relevant features. We show the band structure engineering of potential topological materials LnSb1-xBixTe (Ln = La, Ce, Pr; x ~ 0.2) and CeBiTe. Continuing our search for novel quantum materials, our elucidation of crystal growth parameters of Ce-based intermetallics, led to the identification of a new intermetallic homologous series An+1MnX3n+1 (A = rare earth; M = transition metal; X = tetrels; n = 1 – 6) built up of structural subunits such as AlB2, AuCu3, and BaNiSn3. The homologous series serves as a model system for studying the coupling between localized f-electrons and conduction electrons. Additionally, the stacking of heterostructural subunits is an exciting way to modify physical properties of related phases, highlighting the importance of structural building blocks as a new avenue to study magnetism and topology. Crystal growth, detailed single crystal structural modeling, and magnetic and transport properties of Ce5Co4+xGe13-ySny (n = 4), Ce6Co5+xGe16-ySny (n = 5), and Ce7Co6+xGe19-ySny (n = 6), are presented. The similarities between the synthetic profiles used to grow n = 4 – 6 brought about new questions which led to our work investigating phase formation. Finally, the process for designing in situ synchrotron experiments, including a new sample environment and furnace apparatus for the use with flux grown intermetallics, is presented.