Micro‐Raman spectroscopy of natural members along CuSbS2–CuSbSe2 join

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Marco E. Ciriotti
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Micro‐Raman spectroscopy of natural members along CuSbS2–CuSbSe2 join

Messaggio da Marco E. Ciriotti » mer 15 ago, 2018 19:49

Referenza:
▪ Sejkora, J., Buixaderas, E., Škácha, P., Plášil, J. (2018): Micro‐Raman spectroscopy of natural members along CuSbS2–CuSbSe2 join. Journal of Raman Spectroscopy, 49, 1364–1372.

Abstract:
Micro‐Raman spectroscopy was used to investigate the natural orthorhombic members (space group Pnma) along the CuSbS2–CuSbSe2 join: chalcostibite Cu1.01Sb1.00S1.99 from Dúbrava (Slovak Republic); Se‐rich chalcostibite Cu1.00(Sb0.99As0.02)Σ1.01(S1.29Se0.70)Σ1.99 and the new mineral příbramite Cu0.99(Sb1.03As0.01)Σ1.04(Se1.82S0.15)Σ1.97 both from the Příbram uranium and base‐metal district (Czech Republic). Stretching and bending vibrations of the pyramidal SbS3 groups occur between 350 and 200 cm−1; vibrations of SbSe3 groups are shifted to the range 240–80 cm−1 due to the almost twice heavier mass of Se compared with S. The shift of the ν1 symmetric Sb‐(S,Se) vibration was observed, yielding 113 cm−1, and for the ν3 antisymmetric stretching Sb‐(S,Se), vibration was about 127 cm−1. The wavenumber of the ν1 symmetric Sb–S stretching vibrations decreases with increasing Se content—from 336 (in chalcostibite) over 330 (in Se‐rich chalcostibite) to 326 cm−1 (in příbramite), and a similar situation was observed for the case of ν1 symmetric Sb–Se stretching vibrations from 220 in Se‐rich chalcostibite to 215 cm−1 in příbramite. The trend for the ν3 antisymmetric Sb‐(S,Se) stretching vibrations is the opposite, from 306 cm−1 in chalcostibite to 314 cm−1 in Se‐rich chalcostibite (Sb–S bonds) and from 180 cm−1 in Se‐rich chalcostibite to 185 cm−1 in příbramite (Sb–Se bonds). These small shifts are probably connected with the influencing of the bonding environment of SbS3 and SbSe3 pyramids. The vibrations of Cu‐S(Se) bonds are represented only by less intense bands, and the observed intense bands below 80 cm−1 should correspond to external modes.
Marco E. Ciriotti

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