中国物理B ›› 2019, Vol. 28 ›› Issue (5): 56105-056105.doi: 10.1088/1674-1056/28/5/056105
• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇 下一篇
A revised jump-diffusion and rotation-diffusion model
Hua Li(李华), Yu-Hang Chen(陈昱沆), Bin-Ze Tang(唐宾泽)
- Department of Physics, Jinan University, Guangzhou 510632, China
A revised jump-diffusion and rotation-diffusion model
Hua Li(李华), Yu-Hang Chen(陈昱沆), Bin-Ze Tang(唐宾泽)
- Department of Physics, Jinan University, Guangzhou 510632, China
摘要：
Quasi-elastic neutron scattering (QENS) has many applications that are directly related to the development of high-performance functional materials and biological macromolecules, especially those containing some water. The analysis method of QENS spectra data is important to obtain parameters that can explain the structure of materials and the dynamics of water. In this paper, we present a revised jump-diffusion and rotation-diffusion model (rJRM) used for QENS spectra data analysis. By the rJRM, the QENS spectra from a pure magnesium-silicate-hydrate (MSH) sample are fitted well for the Q range from 0.3 Å-1 to 1.9 Å-1 and temperatures from 210 K up to 280 K. The fitted parameters can be divided into two kinds. The first kind describes the structure of the MSH sample, including the ratio of immobile water (or bound water) C and the confining radius of mobile water a0. The second kind describes the dynamics of confined water in pores contained in the MSH sample, including the translational diffusion coefficient Dt, the average translational residence time τ0, the rotational diffusion coefficient Dr, and the mean squared displacement (MSD) <u2>. The rJRM is a new practical method suitable to fit QENS spectra from porous materials, where hydrogen atoms appear in both solid and liquid phases.
中图分类号: (Neutron scattering (including small-angle scattering))
- 61.05.fg