Raman spectroscopic evidence of impurity‐induced structural distortion in SmB₆

Abstract

Impurity‐induced structural distortion in SmB6 is suggested by Raman spectroscopy study on impurity‐controlled samples. Significant differences in the Raman spectra of single crystals SmB6(6N), synthesized with 99.9999%‐pure boron, and SmB6(3N), synthesized with 99.9%‐pure boron, are detected. While no noticeable differences are detected in the X‐ray diffraction of SmB6(3N) and SmB6(6N), all the Raman phonon modes of the T2g, Eg, and A1g of SmB6(3N) are clearly broader and shift to higher wavenumbers than those of SmB6(6N), and the T2g and Eg modes of SmB6(3N) show doublet features. Based on the high‐pressure Raman measurements and phonon calculation in uniaxial compression model, we argue that small amount of impurities in SmB6(3N) is enough to induce anisotropic distortion in the B6 octahedra, leading to peculiar behaviors in Raman spectrum of SmB6(3N). Our results may present a clue for understanding the current puzzles about SmB6 of various origins with different impurities.

Selective kinetic growth and role of local coordination in forming Al2TiO5-based coatings at lower temperatures

“…Similar notions have been made within comparable material systems. 109,111,113 In addition, an increased level of lower coordinating cationic sites, indicating the presence of intergrowth phases rather than Al 2 TiO 5 , is derived from the intense, symmetric Raman band around 850-900 cm À1 in Fig. 8.…”

Bridging the gap between atomically thin semiconductors and metal leads

“…1d . Such lattice distortion is different from destructive defects and has been applied to engineer bulk materials’ properties 27 , 28 , while it has not been reported in TMDSCs yet. It is also different from the common H-to-T phase transition in TMDSCs by its nanoscale sizes and tunable work functions (Supplementary Fig.…”

Evolution of Pressure-induced Shear Amorphization in Rare-earth Hexaboride

“…Therefore, both T 2g and E g modes are modulating the B-B-B bond angles, whereas, A 1g mode is related to the stretching of B-B bond 13 . From residual indent (Fig.…”

“…2(b) are related to the vibrations of octahedral B 6 . The E g mode is associated with compressing up and down vibrations, while T 2g mode is related to the scissoring displacement of B atoms in the octahedral B 6 13 .…”