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Ordered low-temperature structure in K4C60 detected by infrared spectroscopy

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 نشر من قبل Katalin Kamaras
 تاريخ النشر 2001
  مجال البحث فيزياء
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 تأليف K. Kamaras




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Infrared spectra of a K4C60 single-phase thin film have been measured between room temperature and 20 K. At low temperatures, the two high-frequency T1u modes appear as triplets, indicating a static D2h crystal-field stabilized Jahn-Teller distortion of the (C60)4- anions. The T1u(4) mode changes into the known doublet above 250 K, a pattern which could have three origins: a dynamic Jahn-Teller effect, static disorder between staggered anions, or a phase transition from an orientationally-ordered phase to one where molecular motion is significant.



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