Intrinsic extremely low thermal conductivity in BaIn2Te4: Synthesis, crystal structure, Raman spectroscopy, optical, and thermoelectric properties

Ternary Chalcogenides BaMxTe2 (M = Cu, Ag): Syntheses, Modulated Crystal Structures, Optical Properties, and Electronic Calculations

“…These bands can be compared with the Ag–Te stretching modes of 80, 110, and 138 cm –1 in Ag 2 Te . The bands at 667 and 732 cm –1 are Ba–Te stretching modes, which are in good agreement with the Ba–Te stretching frequencies in BaIn 2 Te 4 (667 and 732 cm –1 ) and Ba 3 ScTe 5 (671.5 and 730 cm –1 ) …”

“…The reflectance data were converted to absorption data by using the Kubelka–Munk equation: here α, R , and S are the absorption coefficient, the reflectance, and the scattering coefficient, respectively. The bandgap was estimated by using the Tauc plot: here α, h , and υ are absorption coefficient, Planck’s constant, and frequency of light, respectively. E g is the bandgap and A is a proportionality constant.…”

“…(667 cm −1 and 732 cm −1 ) 33 and Ba3ScTe5 (671.5 cm −1 and 730 cm −1 ). 11 shows the presence of Ag−Te (83, 116, and 139 cm −1 ) and Ba−Te vibrations (667 cm −1 and 732 cm −1 ).…”

Synthesis and Characterizations of Two Tellurides β-BaGa2Te4 and Ba5Ga2Ge3Te12 with Flexible Chain Structure

“…5730(5) Å (Figure2c), which are similar to those of 3.580 Å in BaIn 2 Te 4 35. Compared with β-BaGa 2 Te 4 , α-BaGa 2 Te 4 crystallizes in the I4/mcm space group (No.140).…”

“…It can be considered that the crystal structure of β-BaGa 2 Te 4 is composed of one-dimensional (1D) [GaTe 2 ] chains arranged according to a primitive rod-packing with the Ba 2+ cations residing in the interstices built by four of these chains (Figure a). The Ba 2+ cations are coordinated with eight Te atoms to form into an irregular [BaTe 8 ] decahedron with d (Ba–Te) = 3.5397(5)–3.5730(5) Å (Figure c), which are similar to those of 3.580 Å in BaIn 2 Te 4 …”