A theoretical calculation of the orbital g‐factor of the excited state of F‐centres in alkali halides

Abstract

Using a model similar to that of Smith [4] the orbital g‐factor gorb. of the excited state of F‐centres in LiF, LiCl, NaF, NaCl, KF, and KCl was calculated. The results are quite sensitive to the particular envelope wavefunction chosen for the F‐centre. Gourary and Adrian type II wavefunctions lead to results which are in good agreement with the available experimental values.

Magneto-optical properties of the excited state of f- centres in some alkali-halides : addendum

“…A definite trend is visible on figure la and also (though less clearly) on figure lb : g is predicted to increase with cation size and to decrease with the anion size (with the exception of Cland Br-, 9 which are calculated to yield comparable results). A similar smooth dependence of g both on the cation size and the anion size was found in analogous, but less extensive, calculations we performed a few years ago [10].…”

“…3.2 ORBITAL g-FACTORS. -Harker [1 has performed four calculations of g : he uses either a point-ion u or an ion-size u ; he employs either Thuau and Margerie [10]'s formula for gorb (gradient) or Smith [11]'s modification of this formula (dipole) (1). These four results are tabulated in the four last columns of table II.…”

“…These three terms are expected to increase both with the size of the cation and with the size of the anion. From our previous calculations [10], we have been able to evaluate these three terms for several alkali-halides and to show that the first and third are negative, the second positive and that there is a considerable amount of cancellation among them : the algebraic sum of three large terms yields a comparatively small calculated g-shift. Therefore, it seems rather hazardous to try to deduce from Smith's picture something about the physical origin of the predicted ion size dependence of Ag.…”

“…Thuau and Margefie [10] or Harker [1] are necessary to account correctly for the variations of g among the alkali-halides.…”

Magnetic circular dichroism of the vibrationally induced d → d transition 4A2g(F) → 4T1g(P)on Co2+ ions in CdF2

“…This value may be different from that of the free ion due to the presence of the crystal field and covalency. Experimentally as well as theoretically one normally obtains values lower than 1 for F-centres [20]. But also values above 1 were found [14].…”