Temperature and pressure dependence of intervalence charge transfer bands in spectra of some Fe- and Fe, Ti-bearing oxygen-based minerals
Taran, M. N.; Langer, K.
published: May 1, 1998
ArtNo. ESP154017202010, Price: 29.00 €
The electronic absorption spectra, in the UV to NIR spectral range, of oxygen-based, transition metal ion-bearing minerals contain bands caused by single 3 dN-ion dd-transitions, eventually affected by ECP- (exchange coupled-pair-) effects, and IVCT-transitions, e.g. of homonuclear Fe2 + Fe3 + - (I) or heteronuclear Fe2 + Ti4 + - systems (II) occurring most often in rock-forming minerals. To differentiate among these different origins of absorption bands, it is suggested to use the pressure- and temperature-dependencies of their characteristics, i.e. of their energy v [cm-'], integral intensity A = ( lit) *J' Ig (loll) dv [cm- 2 j and full band width at half height V Y2 [cm-' ]. The paper contributes to the elucidation of such effects for IVCT in Fe2 + Fe3 + - (I) and Fe2 + Ti4 + -systems (II) in corundum (I, II), clinopyroxene (I), phlogopite (I), Fe -cordierite (I), riebeckite (I), dravite (II) and dumortierite (II).