Open AccessIn situ synchrotron X‐ray powder diffraction for studying the role of induced structural defects on the thermoluminescence mechanism of nanocrystalline LiF
Author(s) -
El Ashmawy Mostafa,
Amer Hany,
Abdellatief Mahmoud
Publication year - 2016
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s1600577516000680
Subject(s) - nanocrystalline material , materials science , microstructure , thermoluminescence , powder diffraction , isothermal process , ball mill , diffraction , crystallography , synchrotron , x ray crystallography , composite material , luminescence , nanotechnology , optics , chemistry , thermodynamics , optoelectronics , physics
The correlation between the thermoluminescence (TL) response of nanocrystalline LiF and its microstructure was studied. To investigate the detailed TL mechanism, the glow curves of nanocrystalline LiF samples produced by high‐energy ball‐milling were analyzed. The microstructure of the prepared samples was analyzed by synchrotron X‐ray powder diffraction (XRPD) at room temperature. Then, the microstructure of a representative pulverized sample was investigated in detail by performing in situ XRPD in both isothermal and non‐isothermal modes. In the present study, the dislocations produced by ball‐milling alter the microstructure of the lattice where the relative concentration of the vacancies, responsible for the TL response, changes with milling time. An enhancement in the TL response was recorded for nanocrystalline LiF at high‐temperature traps (after dislocations recovery starts >425 K). It is also found that vacancies are playing a major role in the dislocations recovery mechanism. Moreover, the interactions among vacancies–dislocations and/or dislocations–dislocations weaken the TL response.