Dy. Smith et Ms. Malghani, OPTICAL DETERMINATION OF THE SPATIAL EXTENT OF DEFECTS IN INSULATORS, Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms, 141(1-4), 1998, pp. 42-48
We have studied the size of common electron-excess defects using the V
inti sum rule that relates the mean-square radius of a defect's ground
state to its optical absorption spectrum. Here we present the single-
electron sum-rule theory and consider its many-electron extension. We
show that numerous electron-excess defects in highly ionic systems, in
cluding F centers and substitutional s(2) impurity anions, are highly
localized, primarily to a single lattice site. Similar defects in alka
line-earth oxides and sulfides are more diffuse, presumably because of
greater covalent mixing between quantum states of the defect and the
host. (C) 1998 Published by Elsevier Science B.V. All rights reserved.