TEMPERATURE-DEPENDENT HOLE-BURNING STUDY OF DYE MOLECULES ADSORBED ON METAL-OXIDE POWDERS

We report on the investigation of quinizarin adsorbed to the surface of gamma-alumina powder with persistent spectral hole-burning. In this particular material the chromophore is strongly bound (chemisorbed) to the surface, and it was shown that the holewidth at 1.6 K is narrower than for other dye-surface systems. The temperature dependence of the hole-burning linewidth between 1.6 and 10 K was best fitted by a combination of a T-alpha law and weaker contribution from an exponentially activated process, the T-alpha contribution referring to the glass-like nature of the disordered gamma-alumina surface.