Study on luminescence properties of Nd3+–La3+ and Nd3+–Sc3+ codoped M′-LuTaO4 phosphors

• The decay time of Nd:LuTaO4 is shortened by doping La3+ or Sc3+ ion.
• The decay of Nd/La:LuTaO4 increases with the increase of La content.
• The decay of Nd/Sc:LuTaO4 decreases with the increase of Sc content.
• The mechanism is discussed respectively.

Nd3+ doped M′-LuTaO4 phosphor, with high density (9.8 g/cm3) and relatively fast decay time (261 ns), is a potential heavy scintillator. In this work, Nd:LuTaO4 is codoped with La3+ or Sc3+ ion and its structure and luminescent properties as a function of their concentration are studied. The structural parameters are obtained by Rietveld refinement. The strongest emission peak is located at 419 nm which corresponds to the 4D3/2 → 4I13/2 transition of Nd3+. The decay times of 4D3/2 → 4I13/2 transition in Nd/La:LuTaO4 and in Nd/Sc:LuTaO4 are much shorter than that in Nd:LuTaO4, which decrease to 211 ns and 163 ns, respectively. It is also found that the decay time of 4D3/2 → 4I13/2 transition in Nd/La:LuTaO4 increases with the increase of La content, and the decay time of 4D3/2 → 4I13/2 transition in Nd/Sc:LuTaO4 decreases with the increase of Sc content. Besides, the mechanism is discussed respectively.