The pressure dependence of the luminescence from the F-7(1,2) <-- 5D0
transitions of Eu3+ ion in EuVO4 has been investigated to 5.6 GPA usin
g a diamond anvil cell. At ambient pressure two of the F-7(1) <-- 5D0
transitions are degenerate in the zircon-type phase of EuVO4; however
this degeneracy is removed with the application of pressure (greater-t
han-or-equal-to 0.8 GPA). Abrupt changes in the luminescence spectrum
from the Eu3+ ion were observed at 4.5 GPA, which remained even after
removal of pressure, indicating that a pressure-induced, irreversible
phase transition had occurred. The Eu3+ ion luminescence spectrum from
the high-pressure, scheelite-type phase of EuVO4 exhibited the charac
teristics of a distorted D2d symmetry instead of the S4 site symmetry
determined from the results of X-ray diffraction analysis. The effect
of pressure on the energy levels of the Eu3+ ion in EuVO4 is discussed
.