Electronic Resource
Classical infrared spectra of ionic crystals and their relevance for statistical mechanics
| العنوان: | Classical infrared spectra of ionic crystals and their relevance for statistical mechanics |
|---|---|
| المؤلفون: | Carati, A, Galgani, L, Maiocchi, A, Gangemi, F, Gangemi, R, Carati A., Galgani L., Maiocchi A., Gangemi F., Gangemi R. |
| بيانات النشر: | Elsevier B.V. 2018 |
| نوع الوثيقة: | Electronic Resource |
| مستخلص: | It was recently shown that the experimental infrared spectra of ionic crystals at room temperature are very well reproduced by classical realistic models, and here new results are reported on the temperature dependence of the spectra, for the LiF crystal. The principal aim of the present work is however to highlight the deep analogy existing between the problem of spectra in ionic crystal models on the one hand, and that of energy equipartition in the Fermi–Pasta–Ulam model, on the other. Indeed at low temperatures the computations of the spectra show that the dynamics of the considered system is not completely chaotic, so that the use of the Boltzmann–Gibbs statistics is put in question, as in the Fermi–Pasta–Ulam case. Here, however, at variance with the equipartition problem, a first positive indication is given on the modifications that should be introduced in a classical statistical treatment: the new results at low temperatures show that it is indeed the Clausius identification of temperature that has to be modified. In fact, at very low temperatures the theoretical spectra fail to reproduce the experimental ones, if the temperature is taken as proportional to mean kinetic energy, but agreement is recovered through the only expedient of introducing a suitable temperature rescaling. Analogous results are also found in connection with thermal expansion. |
| مصطلحات الفهرس: | Equipartition principle, FPU model, Infrared spectra, Ionic crystal model, Ordered and chaotic motions, info:eu-repo/semantics/article |
| URL: | info:eu-repo/semantics/altIdentifier/wos/WOS:000437077400001 volume:506 firstpage:1 lastpage:10 numberofpages:10 journal:PHYSICA. A |
| الاتاحة: | Open access content. Open access content info:eu-repo/semantics/closedAccess |
| ملاحظة: | English |
| Other Numbers: | ITBAO oai:boa.unimib.it:10281/334581 10.1016/j.physa.2018.04.070 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85045646601 1308941212 |
| المصدر المساهم: | BICOCCA OPEN ARCH From OAIster®, provided by the OCLC Cooperative. |
| رقم الانضمام: | edsoai.on1308941212 |
| قاعدة البيانات: | OAIster |
| الوصف غير متاح. |