Aggregate color center formation processes in lithium fluoride crystals after irradiation
Aggregate color center formation processes in lithium fluoride crystals after irradiation
复制标题
氟化锂晶体辐照后聚集色心的形成过程
DOI：
10.1007/s10812-011-9413-1
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发表时间：
2011
影响因子：
0.7
通讯作者：
G. Baldacchini
中科院分区：
文献类型：
--
作者：
A. P. Voitovich;M. Voitikova;V. Kalinov;E. F. Martynovich;A. N. Novikov;L. P. Runets;A. Stupak;R. Montereali;G. Baldacchini
在77K温度下用不同剂量的γ光子辐照氟化锂晶体。我们测量了不同退火温度以上的阴离子空位迁移率的温度的色心的聚集动力学。结果表明，随着辐照剂量的增加，空位的寿命减小，而中心的寿命增加。我们解释这些类型的依赖性的基础上的聚集过程中的色心在辐射后的时期。我们确定的时间常数和能量（类似于活化能的Arrhenius方程）的各种过程中，涉及的浓度的上升和下降的聚集色心。根据所获得的实验数据，我们建立了辐射后F2和F2中心的形成过程。F2心是由空位ν a加入心中形成的。在第一个快速阶段，在晶体辐照过程中产生的空位参与了它们的产生。在长的最后阶段，空位被使用，其出现在辐射后时期，在晶格位置处发生反应+ H → νa+氟离子，其中H是间隙氟原子。这些中心是由F1心和F2心合并而成的，也是空位对F2心的补充。在这种情况下，使用不仅在晶体的照射期间而且在照射后时段中产生的空位。中心浓度的上升比F2中心浓度的上升快。
Lithium fluoride crystals were irradiated by different doses of gamma photons at a temperature of 77 K. We measured the aggregation kinetics for the color centers with different annealing temperatures above the temperature of anion vacancy mobility. We show that the lifetimes of the vacancies decrease while the lifetimes of thecenters increase as the irradiation dose increases. We explain these types of dependences based on the aggregation processes for color centers in the post-radiation period. We determine the time constants and energies (analogous to activation energies in the Arrhenius equation) for the various processes involving rise and fall in the concentration of aggregate color centers. Based on the experimental data obtained, we have established the processes formingF2andcenters in the post-radiation period. TheF2centers are formed when vacancies νaadd tocenters. Vacancies arising during irradiation of the crystal participate in their creation in the first fast stage. In the long final stage, vacancies are used which appear in the post-radiation period on occurrence of the reaction+ H → νa+ fluoride ion at the lattice site, where H is an interstitial fluorine atom. Thecenters are formed both by mergingandF1centers and as a result of addition of vacancies toF2centers. In this case, vacancies are used that are generated not only during irradiation of the crystal but also in the post-radiation period. The rise in the concentration ofcenters occurs faster than the rise in the concentration ofF2centers.