Li1.3Eu0.3Ti1.7(PO4)3 and Li1.3Al0.3Ti1.7(PO4)3 doped with Eu3+ and Al
3+ ions have been prepared by solid state reaction. It was found that
the dopant Eu3+ ions enhanced the ionic conductivity of LiTi2(PO4)3 wi
th the same increment as that of Al3+ ions at different temperatures.
The mechanism has been investigated by XRD and luminescence probe. The
result of XRD for Li1.3Eu0.3Ti1.7(PO4)3 indicates that the XRD patter
ns do not change with the doping of Eu3+. Luminescence spectra under v
arious temperatures show that Eu3+ ions locate at the sites with inver
sion symmetry. The above results agree with the assumption that a glas
sy phase Li3Eu2(PO4)3 Might be formed in the grain boundary of LiTi2(P
O4)3, which increases the interface conduction layer and the contact a
rea between grains and therefore may be responsible for the enhanced i
onic conductivity.