Diffusion in concentrated lattice gases. Self-diffusion of noninteracting particles in three-dimensional lattices

1981 ◽  
Vol 23 (10) ◽  
pp. 4931-4945 ◽  
Author(s):  
K. W. Kehr ◽  
R. Kutner ◽  
K. Binder
Keyword(s):  
Three Dimensional ◽  
Lattice Gases ◽  
Self Diffusion

Self-Diffusion and Reorientation of Methylammonium Ions in (CH3NH3)2ZnCl4 Crystals as Studied by 1H-NMR

1989 ◽  
Vol 44 (8) ◽  
pp. 741-746 ◽  
Author(s):  
Hiroyuki Ishida ◽  
Tadashi Iwachido ◽  
Naomi Hayama ◽  
Ryuichi Ikeda ◽  
Mifune Terashima ◽  
...  
Keyword(s):  
Solid Phase ◽  
Relaxation Times ◽  
Three Dimensional ◽  
Lattice Relaxation ◽  
High Temperature Phase ◽  
Spin Lattice Relaxation ◽  
Temperature Phase ◽  
Scanning Calorimetry ◽  
Self Diffusion ◽  
H Nmr

Abstract Differential thermal analysis, differential scanning calorimetry, and measurements of the 1H spin-lattice relaxation times and second moments of 1H-NMR absorptions were performed on methylammonium tetrachlorozincate (II) crystals over a wide temperature range. A solid-solid phase transition was located at 477 K. From the 1H-NMR experiments it was found that the cations undergo overall reorientation as well as three dimensional translational self-diffusion in the high-temperature phase. In the low-temperature phase, a 120° reorientational motion of the CH3 and NH3+ groups of the cation about its C-N bond axis was detected. The parameters for the motional modes of the cations in the crystal were evaluated from the analysis of the 1H-NMR experimental results.

scholarly journals Three-dimensional pulsed field gradient NMR measurements of self-diffusion in anisotropic materials for energy storage applications

2019 ◽  
Vol 21 (8) ◽  
pp. 4538-4546 ◽  
Author(s):  
S. Engelke ◽  
L. E. Marbella ◽  
N. M. Trease ◽  
M. De Volder ◽  
C. P. Grey
Keyword(s):  
Energy Storage ◽  
Porous Silicon ◽  
Field Gradient ◽  
Three Dimensional ◽  
Pulsed Field ◽  
Self Diffusion ◽  
Silicon Structures ◽  
Energy Storage Applications ◽  
Nmr Methods ◽  
Pfg Nmr

The ability to resolve solvent in- and outside of the pores of mesoscopic porous silicon structures allows the effect of confinement on transport to be explored by 1H and 7Li PFG NMR methods and pore diameters and lengths to be estimated.

scholarly journals Atomistic Simulations of the Defect Chemistry and Self-Diffusion of Li-ion in LiAlO2

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2895 ◽  
Author(s):  
N. Kuganathan ◽  
J. Dark ◽  
E.N. Sgourou ◽  
Y. Panayiotatos ◽  
A. Chroneos
Keyword(s):  
Atomistic Simulation ◽  
Three Dimensional ◽  
Atomistic Simulations ◽  
Intrinsic Defect ◽  
Lithium Content ◽  
Frenkel Defect ◽  
Self Diffusion ◽  
Simulation Techniques ◽  
Lithium Diffusion ◽  
Li Ion

Lithium aluminate, LiAlO2, is a material that is presently being considered as a tritium breeder material in fusion reactors and coating material in Li-conducting electrodes. Here, we employ atomistic simulation techniques to show that the lowest energy intrinsic defect process is the cation anti-site defect (1.10 eV per defect). This was followed closely by the lithium Frenkel defect (1.44 eV per defect), which ensures a high lithium content in the material and inclination for lithium diffusion from formation of vacancies. Li self-diffusion is three dimensional and exhibits a curved pathway with a migration barrier of 0.53 eV. We considered a variety of dopants with charges +1 (Na, K and Rb), +2 (Mg, Ca, Sr and Ba), +3 (Ga, Fe, Co, Ni, Mn, Sc, Y and La) and +4 (Si, Ge, Ti, Zr and Ce) on the Al site. Dopants Mg2+ and Ge4+ can facilitate the formation of Li interstitials and Li vacancies, respectively. Trivalent dopants Fe3+, Ni3+ and Mn3+ prefer to occupy the Al site with exoergic solution energies meaning that they are candidate dopants for the synthesis of Li (Al, M) O2 (M = Fe, Ni and Mn) compounds.

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