Antiresonance in the Optical Spectrum of Eu3+ in Eu3Ga5O12:Pt
Abstract
The absorption line shape of the Eu3+ 7F0-to-5D0 transition is severely modified in garnet crystals where there is an overlapping absorption band from an impurity such as Pt. Below 77 °K the transition has a dispersionlike line shape which changes as the temperature is increased to an approximate antiresonance at 300 °K. The absorption was fitted to Fano's line-shape formula and the four parameters were obtained as a function of temperature. Weak antiresonances are also observed near the 7F0 to 5D1 transitions. A two-ion model consisting of one ion with sharp-line states and a second with a broad absorption band is shown to reproduce Fano's line-shape formula. The interion coupling results from a transfer of excitation between the sharp line and the band and the coupling is shown to be consistent with an anisotropic superexchange interaction.
- Publication:
-
Physical Review B
- Pub Date:
- September 1973
- DOI:
- 10.1103/PhysRevB.8.1835
- Bibcode:
- 1973PhRvB...8.1835V