The structural solution and physical property characterization of several Ln-T-Al/Ga and Ln-T-Al-Si contain phases, which include Ln(Cu,Al)12 (Ln = Y, Ce, Pr, Sm, and Yb), Ln(Ag,Al,Si)2 (Ln = Ce and Gd), LnCu2(Al,Si)5 (Ln = La and Ce), Ln(Cu,Al,Ga)13-x (Ln = La, Ce, Pr, and Eu), α and β LnNiGa4 (α Ln = Y and Gd – Yb; β Ln = (Tb – Er)), and Ln4FeGa12 (Ln = Tb – Er) will be presented in this work with an emphasis on crystal growth. The systems cover a large breadth of phase space and serve to illustrate the new and rich chemistry and physics that remain, to this day, to be discovered in these phase spaces. Additionally, these phases range in complexity, to the eloquently simple open network found in Ln(Ag,Al,Si)2 to the more complex 3 dimensional polyhedral environments of Ln(Cu,Al)12 (Ln = Y, Ce, Pr, Sm, and Yb) or Ln(Cu,Al,Ga)13-x. In all cases these phases were discovered from systematic progressions throughout the periodic table and can all trace their roots to one phase, CePdGa6. Chapter 1 of this document describes the logic and motivation behind the exploration of the Ln-Cu-Al phase space and alludes to some serendipitous discoveries. Additionally, it treats the issues of a failing materials science effort in America as recently outline in a recent National Academies of Science document: Frontiers in Crystalline Matter: From Discovery to Technology. Time is taken to discuss what is needed to once again assume a predominate role in these ventures and how our group aligns itself with the proposed directives Chapters 2 – 5 provide in-depth discussion of selected phases as it relates to their respective crystalline growth, structure, magnetic, and transport properties
