Magneto‐Optical Properties of F Center in KCI:SH⁻

Abstract

The magnetic circular dichroism (MCD) of F 2+ centers in KCI:SH− has been measured in absorption in the 1sσg → 2pyπu transitions at 493 and 509 nm, with fields up to 5 T and in the temperature range 1.5 K < T < 77 K. Within the limit of detection, no MCD is observed in the near infrared transition 1ss̀g → 2ps̀u as well as in both emissions 2pσu → Iss̀g and 2ps̀g. The optical detection of EPR in the F 2+ ground state presents an isotropic single band with g = 1.965 ± 0.007. The spin‐lattice relaxation measured at H = 0.32 T is typical of a direct process T−1 = 4.3 × 10−2 coth (gμBH/2kBT). The spectral variation of the MCD is calculated using perturbation theory to first order. The Hamiltonian includes the spin‐orbit interaction in the 2pπu excited state and the orbital molecular wave functions are obtained by a linear combination of 1s and 2p atomic orbitals. The calculated MCD is in good agreement with the observed one, for the spin‐orbit interaction strength σz = 3.6 meV.