Relationships between electron paramagnetic resonance parameters and the crystal
structure of Fe3+:ZnO crystals were established. On this basis, the electron
paramagnetic resonance parameters D, (a-F) and the zero-field splitting δ1, δ2 of the
ground state for Fe3+ in Fe3+:ZnO crystals were theoretically investigated by using
the complete diagonalization method. The theoretical second-order electron
paramagnetic resonance parameter, D, the fourth-order electron paramagnetic
resonance parameter, (a-F), and the zero-field splitting of the ground state: δ1, δ2
for Fe3+ in Fe3+:ZnO yielded good agreement with experiment when the three O2-
ions below the Fe3+ ion rotated by 0.475 to 0.562°, away from the [111] axis. Thus,
the local structural distortion effect played an important role in explaining the
spectroscopic properties of Fe3+ ions in Fe3+:ZnO crystals. The present approach
took account of spin-orbit interaction as well as of spin-spin, spin-other-orbit and
orbit-orbit interactions omitted from previous studies. This showed that, although
the spin-orbit interaction was the most important one, the contributions due to the
electron paramagnetic resonance parameters from the other three interactions were
appreciable and shoulfnot be omitted, especially for the electron paramagnetic
resonance parameter, D.
Studies of the EPR Parameters and Defect Structure for Tetrahedral Fe3+ Centers
in Zinc Oxide. Z.Y.Yang: Physica Status Solidi B, 2009, 246[8], 1919-24