Energy migration in randomly doped crystals : geometrical properties of space and kinetic laws
Energy migration in randomly doped crystals : geometrical properties of space and kinetic laws
复制标题
随机掺杂晶体中的能量迁移:空间几何特性和动力学定律
DOI:
10.1051/jphys:0198300440110121700
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发表时间:
1983
期刊:
影响因子:
--
通讯作者:
P. Evesque
中科院分区:
文献类型:
--
作者:
P. Evesque
The kinetics of energy migration in the excited states of doped crystals are calculated using a percolation model. Special care has been taken in the case where an annhihlation process controls the density n of excitations at time t. In this case the number I of fusions per unit of time follows the laws: I∼t − α (with α=1−d(1−e)/2) at short times, I∼t − β (with β=1+d(1+e)/2) at longer times, I∼t −2 at very long times. d is the spectral dimension of Alexander and Orbach, and e is related to the other classical percolation exponents through e=β/(β+γ). The applicability of this theory to randomly doped crystals with short-range interactions is then discussed. A new experimental result which has been obtained in a naphthalene D 8 crystal doped with naphthalene H 8 is given. These experimental and theoretical results are in relatively good agreement Etude des lois cinetiques de la migration d'energie dans les etats excites de cristaux dopes a l'aide d'un modele de percolation, en particulier dans le cas ou la densite d'excitations est regie par un processus d'annihilation. Loi de decroissance du nombre I de fusions par unite de temps: en t − α (avec α=1−d(1−e)/2) aux temps courts, en t−β (avec β=1+d(1+e)/2) aux temps plus longs, en t −2 aux temps tres longs (si d est l'exposant spectral d'Alexander et Orbach, et e est relie aux exposants critiques de percolation par e=β/(β+γ)). Domaine d'application de cette theorie. Resultat experimental pour un cristal de naphtalene D 8 dope par du naphtalene-H 8