AN OVERVIEW OF THE PHOTOACOUSTIC PHASE SPECTRA OF RARE-EARTH COMPLEXES

The photoacoustic(PA) amplitude and phase spectra of several kinds of rare earth (RE) complexes are reported and summarized briefly. It is o bserved that both the amplitude and phase spectra well characterize th e different energy levels of the RE complexes. The phase angle of the RE complexes is associated with the relaxation time tau and the optica l absorption coefficient beta concerning with the pi-pi transition an d the f-f transitions, respectively. After individual detailed discuss ion of the phase spectra, a reasonable theoretical consideration is gi ven to interpret the results.