PRESSURE EFFECTS ON THE ABSORPTION-SPECTRA OF KBR-AG+

Absorption bands A, B, and D in KBr:Ag+ have been investigated under h ydrostatic pressure at low temperature. The pressure shifts of these b ands at 85 K are A: 5.093+0.14p-0.012p(2) eV, B : 5.343+n0.05p+0.006p( 2) eV, and D: 5.882+0.13p-0.016p(2) eV, where pressure p is given in G Pa units. The absorption intensity decreases and the half width become s narrower under higher pressure. The pressure dependence of the peak position is analyzed by taking into consideration the ligand field int eraction in addition to Drickamer's framework. The rather large blue s hift is attributed to the enhancement of the ligand field under pressu re, and the different shift rate (0.08 similar to 0.09 eV/GPa) between the A(D) and B bands results from the ligand field splitting of the d electron. It is suggested that the adiabatic potential in the excited states is deformed in Q(T-1u) space. The changes of adiabatic potenti al in both the configuration coordinates of Q(A(1g)) and Q(T-1u) are d iscussed.