Low temperature studies in LiF:Mg,Cu,P.
Despite extensive investigations carried out in LiF:Mg,Cu,P, the nature of the emission centre is not clearly understood. Results of X ray excited emission in this material at room temperature and at 16 K are presented to obtain more data that can throw light on the emission characteristics of this material. At room temperature only a single emission peak is seen around 390 nm but at 16 K the emission appears to consist of more than one emission band. The emission spectra could be fitted with three bands with peaks at 332, 385 and 447 nm. The X ray excited emission at 16 K after annealing at 573 K for 5 min suppresses the 332 nm emission but enhances 447 nm emission. Moreover, annealing at 573 K greatly reduces the emission intensity, which signifies that the luminescent centres are also destroyed in this process. Temperature-dependent X ray excited fluorescence below room temperature provides evidence of the existence of shallow traps, which give rise to a thermoluminescence peak around 130 K. On the basis of the present investigations it is proposed that the complex nature of the emission may be related to the formation of donor-acceptor pairs in this material. The possible nature of this donor-acceptor complex is discussed.
Mathur
V K
VK
Naval Surface Warfare Center, Carderock Division, Bethesda, MD 20817, USA. mathurvk@nswccd.navy.mil
Bandyopadhyay
P K
PK
Barkyoumb
J H
JH
Cai
G G
GG
D003300:Copper / Q000737:chemistry; D005453:Fluorescence; D005459:Fluorides / Q000737:chemistry / Q000528:radiation effects*; D018020:Lithium Compounds / Q000737:chemistry / Q000528:radiation effects*; D008274:Magnesium / Q000737:chemistry; D010758:Phosphorus / Q000737:chemistry; D011854:Radiochemistry; D013057:Spectrum Analysis; D013696:Temperature; D013819:Thermoluminescent Dosimetry / Q000379:methods* / Q000706:statistics & numerical data; D014965:X-Rays
D018020:Lithium Compounds; C027651:lithium fluoride; D010758:Phosphorus; D003300:Copper; D008274:Magnesium; D005459:Fluorides