中国物理B ›› 2019, Vol. 28 ›› Issue (6): 66401-066401.doi: 10.1088/1674-1056/28/6/066401

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Calculation of the infrared frequency and the damping constant (full width at half maximum) for metal organic frameworks

M Kurt, H Yurtseven, A Kurt, S Aksoy   

  1. 1 Department of Physics, Çanakkale 18 Mart University, 17100 Çanakkale, Turkey;
    2 Department of Physics, Middle East Technical University, 06531 Ankara, Turkey;
    3 Lapseki İÇDAŞ ÇİB MTAL High School, 17100 Çanakkale, Turkey
  • 收稿日期:2019-01-28 修回日期:2019-04-10 出版日期:2019-06-05 发布日期:2019-06-05
  • 通讯作者: M Kurt E-mail:mkurt@comu.edu.tr

Calculation of the infrared frequency and the damping constant (full width at half maximum) for metal organic frameworks

M Kurt1, H Yurtseven2, A Kurt3, S Aksoy1   

  1. 1 Department of Physics, Çanakkale 18 Mart University, 17100 Çanakkale, Turkey;
    2 Department of Physics, Middle East Technical University, 06531 Ankara, Turkey;
    3 Lapseki ?ÇDA? Ç?B MTAL High School, 17100 Çanakkale, Turkey
  • Received:2019-01-28 Revised:2019-04-10 Online:2019-06-05 Published:2019-06-05
  • Contact: M Kurt E-mail:mkurt@comu.edu.tr

摘要:

The ρ(NH2) infrared (IR) frequencies and the corresponding full width at half maximum (FWHM) values for (CH3)2NH2FeM(HCOO)6 (DMFeM, M=Ni, Zn, Cu, Fe, and Mg) are analyzed at various temperatures by using the experimental data from the literature. For the analysis of the IR frequencies of the ρ (NH2) mode which is associated with the structural phase transitions in those metal structures, the temperature dependence of the mode frequency is assumed as an order parameter and the IR frequencies are calculated by using the molecular field theory. Also, the temperature dependence of the IR frequencies and of the damping constant as calculated from the models of pseudospin (dynamic disorder of dimethylammonium (DMA+) cations)-phonon coupling (PS) and of the energy fluctuation (EF), is fitted to the observed data for the wavenumber and FWHM of the ρ (NH2) IR mode of the niccolites studied here. We find that the observed behavior of the IR frequencies and the FWHM of this mode can be described adequately by the models studied for the crystalline structures of interest. This method of calculating the frequencies (IR and Raman) and FWHM of modes which are responsible for the phase transitions can also be applied to some other metal organic frameworks.

关键词: infrared (IR) frequency, full width at half maximum (FWHM), phase transitions, ρ(NH2) mode, niccolites

Abstract:

The ρ(NH2) infrared (IR) frequencies and the corresponding full width at half maximum (FWHM) values for (CH3)2NH2FeM(HCOO)6 (DMFeM, M=Ni, Zn, Cu, Fe, and Mg) are analyzed at various temperatures by using the experimental data from the literature. For the analysis of the IR frequencies of the ρ (NH2) mode which is associated with the structural phase transitions in those metal structures, the temperature dependence of the mode frequency is assumed as an order parameter and the IR frequencies are calculated by using the molecular field theory. Also, the temperature dependence of the IR frequencies and of the damping constant as calculated from the models of pseudospin (dynamic disorder of dimethylammonium (DMA+) cations)-phonon coupling (PS) and of the energy fluctuation (EF), is fitted to the observed data for the wavenumber and FWHM of the ρ (NH2) IR mode of the niccolites studied here. We find that the observed behavior of the IR frequencies and the FWHM of this mode can be described adequately by the models studied for the crystalline structures of interest. This method of calculating the frequencies (IR and Raman) and FWHM of modes which are responsible for the phase transitions can also be applied to some other metal organic frameworks.

Key words: infrared (IR) frequency, full width at half maximum (FWHM), phase transitions, ρ(NH2) mode, niccolites

中图分类号:  (General theory of equations of state and phase equilibria)

  • 64.10.+h
64.60.-i (General studies of phase transitions) 64.70.-p (Specific phase transitions)