Molten metal flux synthesis and crystal growth of intermetallic silicides germanides and indides

Molten metal fluxes have shown themselves to be powerful tools for both crystal growth of known intermetallic compounds, and in the exploratory synthesis of systems containing rare earth metals, transition metals, and a metalloid such as Si B or Ge. Our group has recently launched a research project to explore molten Al and Ga as media to carry out exploratory synthesis of intermetallics of the type RE/TM/Al/Si or Ge when Al is used as a solvent and RE/TM/Ga/Si or Ge when Ga is used. In each case RE is a rare earth metal and TM is some, generally late transition metal. This work has been extremely lucrative producing dozens of new compounds, some of which possess new structure types. It was found that in several cases that the new compounds could only be synthesized by metal flux reactions.; In the present work these concepts are expanded upon and the work with molten Ga is continued. The new boron rich compounds RE3-xC 2Si8(B12)3 (RE = Tb and Er) and beta-SiB 3 were synthesized by the use of liquid Ga, and both crystallize as new structure types. Both compounds are semiconductors and are quite refractory. 2 Intermetallic compounds RENiSi3 (RE = Tb-Er, Yb and Lu) and RE 5Co4Si14 (Dy, Ho, Er, and Tm) were also grown from a Ga flux and their crystal size made characterization of their physical properties possible.; The work was also expanded to include molten indium as a solvent. Using this we were able to trap a new form of RENiGe2, which was determined to be kinetically stable. The near Zintl phase Intermetallic RE2Zn 3Ge6, and the new ordered quaternary variant of the Mg 5Si6 structure RE4Ni2InGe4 were also produced from the In flux. In addition 2 new indium rich ternary compounds REAu2In4 (RE = La-Nd) and YbAu2In 4 were also synthesized. YbAu2In4 shows evidence of a first order valence transition. The crystal structures of these compounds will be discussed as well as selected physical properties.