Interacting Dipoles in Type-I Clathrates: Why Glass-like though Crystal?

Abstract

Almost identical thermal properties of type-I clathrate compounds to those of glasses follow naturally from the consideration that off-centered guest ions possess electric dipole moments. Local fields from neighbor dipoles create many potential minima in the configuration space. A theoretical analysis based on two-level tunneling states demonstrates that interacting dipoles are a key to quantitatively explain the glass-like behaviors of low-temperature thermal properties of type-I clathrate compounds with off-centered guest ions.From this analysis, we predict the existence of a glass transition.

References in corpus (2)

• Glasslike vs. crystalline thermal conductivity in carrier-tuned Ba8Ga16X30 clathrates (X = Ge, Sn)
• Cage-size control of guest vibration and thermal conductivity in Sr8Ga16Si30-xGex