Synthesis and crystal chemistry of new rare-earth metal germanides
Speaker: Silven Bobev, Univ. of Delaware
Date & Time: October 27, 2009 - 11:00am
Location: W/R Auditorium
This talk will highlight some recent discoveries from the Bobev laboratory, dealing with the relationships among the composition, structure, and electronic structure in complex intermetallic compounds and their properties. I will recount the crystal chemistry and the low-temperature physics of several new binary and ternary materials formed between the rare-earth metals and select s- and p-block metals and semi-metals. I will show that despite the apparent complexity in the bonding arrangements, the structures of these compounds can be "broken" down to simpler fragments, which are much easier to describe. This unique aspect of the crystal chemistry allows for the convenient elucidation of the likely geometric and electronic factors that govern the formation of such phases. It also provides a rationale for developing extended series and studying the variations of the structures and properties as functions of the electronegativity and size of the constituent elements.
1."Structure and Bonding in Yb4MgGe4: Yb2+/Yb3+ Mixed Valency and Charge Ordering" Tobash, P. H.; Bobev, S. J. Am. Chem. Soc.2006, 128, 3252
2."Vacancy Ordering in SmGe2-x and GdGe2-x (x = 0.33): Structure and Properties of Two Sm3Ge5 Polymorphs and of Gd3Ge5" Tobash, P. H.; Lins, D.; Bobev, S.; Hur; N.; Thompson, J. D.; Sarrao, J. L. Inorg. Chem.2006, 45, 7286
Host: Jing Li