The photoluminescence and X-ray luminescence of samples of LuTaO4-A (A
=Ti, Pr, Sm, Eu, Gd, Th, Dy, Tm) are reported. The results can be inte
rpreted using simple models. Many samples show pronounced thermolumine
scence after X-ray irradiation at room temperature. Several of the mat
erials possess great potential as X-ray phosphors.