180 keV Mn+ ions were implanted in silica glass at doses ranging
from 1×1016 to 2×1017 ions/cm2 at room
temperature. The coordination structure of implanted Mn atoms was studied by
X-ray absorption spectroscopy. It was found that Mn atoms were mainly
coordinated by O atoms in silica glasses as-implanted at doses lower than
5×1016Mn+ions/cm2. The Mn-O bond
distance was 2.07 Å and the coordination number was 4.3 in average. Mn atoms
were mainly coordinated by Mn and O atoms in the glasses as-implanted at
doses higher than 1×1017 Mn+ions/cm2. In
all the glasses, Mn atoms which are coordinated by O atoms were present as
divalent state. After heating at 700 °C in air, Mn atoms were present as
trivalent state and tended to form oxide crystals.