Mechanoluminescence of Eu2+ doped Sr5 (PO4)3Cl phosphor
A.K.Sahu*,P.S.Chowdhury*,V.Nayar* and S.J.Dhoble ?
Journal Title:Journal of Chemical, Biological and physical sciences
Synthesis of Sr5(PO4)3Cl phosphor by using the solid state diffusion technique. The ML intensity of
Sr5(PO4)3Cl:Eu2+ phosphor increases linearly with time and then it attains a maximum value Im at a
nanosecond of time tm . After tm the ML intensity increases exponentially at a fast rate and then it
decreases exponentially at a slow rate. The ML intensity increases with increasing concentration of Eu,
attains an optimum value for 1 mole %. However there is no considerable change in tm. It is seen that the
ML intensity increases with increasing impact velocity. The ML peak intensity increases with increasing
load. The appearance of ML in Sr5(PO4)3Cl:Eu2+ indicates that the ML in this material may not be due to the
mechanical or electrostatic interaction between the bending segments of dislocations and filled hole traps
, because there is no possibility of dislocations in nanoparticles . Since only one peaks observed in the ML
intensity versus time curve, so it seems that capturing of carries by the shallow traps is not taking place in
this phosphors. The time difference between excitation of two types of defect centres is extremely low .
All the centres responsible for ML excitation are excited all most at the same time.