Abstract
By measuring room temperature infrared (40–35000 cm–1) reflectivity of metallic LuB12 single crystals with different isotopic compositions (natB, 10B, 11B), we find that to model the spectrum we had to introduce, additionally to Drude free-carrier component, a broad excitation with unusually large dielectric contribution (Δe = 8000 ± 4000), which is characterized by a non-Lorentzian lineshape. It is suggested that the origin of the excitation is connected with cooperative dynamics of Jahn–Teller active B12 molecules producing quasilocal vibrations (rattling modes) of caged lutetium ions. The coupling of the Lu3+ rattling motions with the charge carriers of conduction band is proposed to be the reason of strongly damped character of the excitation.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
