Year: 2013
Type: article
Abstract: The optical conductivity spectra of the rattling phonons in the clathrate Ba$_8$Ga$_{16}$Ge$_{30}$ are investigated in detail by use of the terahertz time-domain spectroscopy. The experiment has revealed that the lowest-lying vibrational mode of a Ba(2)$^{2+}$ ion consists of a sharp Lorentzian peak at 1.2 THz superimposed on a broad tail weighted in the lower frequency regime around 1.0 THz. With decreasing temperature, an unexpected linewidth broadening of the phonon peak is observed, together with monotonic softening of the phonon peak and the enhancement of the tail structure. These observed anomalies are discussed in terms of impurity scattering effects on the hybridized phonon system of rattling and acoustic phonons.
Authors: Kei Iwamoto, Shunsuke Kushibiki, Hironori Honda, Shuhei Kajitani, Tatsuya Mori, Hideki Matsumoto, Naoki Toyota, Koichiro Suekuni, Marcos A. Avila, Toshiro Takabatake
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Awards: Novel thermoelectrics emerging from multinary freedoms of clathrates encapsulating rare-earths and alkaline metals, G2594906118, Development of reflection terahertz time-domain spectroscopy and investigation of strongly correlated system derived from rattling phonons, Dynamics of electrical conductions for the materials confined in continuous nano-space, G4159790520, G5055457257, Development of parallelization strategy and speedup technique for 2D quamntum system on many-core parallel machines, Investigations of Lattice Dynamical Properties in Filled Skutterudite Compounds
OpenAlex ID: W2298189745