抄録
The nature of the inhomogeneous broadening of optical spectra has been investigated for Eu3+ ions embedded in pure and impurity ion (Sc3+ or Zr4+) doped Y2O3 crystals. High-resolution absorption spectra of the 7F0–5D0 transitions have been taken as excitation spectra of luminescence. Using optical-radio-frequency (rf) double resonance technique, the distribution of two hyperfine transitions (ω1:Iz=±1⁄2 to ±3⁄2 and ω2:Iz=±3⁄2 to ±5⁄2) in the 7F0 ground state were measured as a function of the optical excitation energy and displayed as a 2-dimensional map on the optical and rf axes. Thus the ionic sites are labeled by three parameters and some new sites were distinguished by using both ω1 and ω2. The single crystals with a disorder systematically controlled by doping of various ions (Sc3+ and Zr4+) were investigated and the character of the inhomogeneous distribution was found to be strongly dependent on the doped ions. By applying the mapping method to the Sc3+ doped Y2O3, the individual sites are discriminated inside the inhomogeneously broadened optical spectra, while the discrete peaks coalesce into a single broad peak in the optical spectrum at higher concentration.
