Peculiarities in the Raman spectra of ZrB12 and LuB12 single crystals

Raman effect in icosahedral boron-rich solids

“…In an earlier Raman study of icosahedral boron-rich compounds, we have carefully tested different methods of sample preparation [5]. Accordingly, the Raman spectra in this study, as far as measured using the Jobin-Yvon Labram spectrometer, were obtained on freshly cleaved samples, ensuring clean and undamaged surfaces.…”

Two-phase zirconium boride thin film obtained by ultra-short pulsed laser ablation of a ZrB12 target

“…Watts et al [20] indicate that this metal boride is only weakly Raman active and exhibits two Raman bands, which are very difficult to be separated from the background [19,20]. On the contrary, Raman spectroscopy has been used to characterize boron compound with MB 12 stoichiometry, showing that the presence of structural imperfection leads to numerous detectable Raman peaks, in the region where only Raman inactive vibrations are expected [15,21,22]. Indeed signals observed in the spectrum in Fig.…”

Effect of electron-phonon coupling on the superconducting transition temperature in dodecaboride superconductors: A comparison ofLuB12withZrB12Teyssier1, Lortz2, Petrović3 et al. 2008Phys. Rev. BSelf Cite474410View full textAdd to dashboardCite

“…It has been shown that the plasma frequencies of these two dodecaborides follow the opposite trend. Even if these materials are extremely good metals in the normal state, the delocalization of the metal ions within the cages ͑demonstrated by using x-ray diffraction 21 ͒ reduces the number of charge carriers. This decrease in the plasma frequency has been quantitatively related to the delocalization effect through band-structure calculations.…”

“…The lattice dynamics were also studied, showing closely related phonon spectra for both compounds. 21 Considering these similarities in the crystal dynamics and electronic structures, the large difference in the superconducting transition temperature in LaB 6 and YB 6 , and ZrB 12 and LuB 12 pairs appears incomprehensible. The hexaborides have been studied by Schell et al 22 but up until now the dodecaborides have not yet been investigated.…”