High spin molecules: ESR of MnF and MnF2 at 4°K

ESR spectra of the MnF and MnF2 molecules trapped in neon and argon matrices have been observed at 4°K. MnF was found to have a 7Σ ground state with the following magnetic parameters in solid neon (assuming g∥=2.002): g⊥=1.999(1), ‖D‖=−0.0107(1) cm−1, ‖A∥(Mn) ‖=490(5), ‖A⊥(Mn) ‖=418(1), ‖A⊥(F) ‖=60(1), and ‖A∥(F) ‖=85(2) MHz. MnF is then highly ionic with the spin density on each F− probably less than about 5%. The Mn+ ion exhibits about 60% of the s character of the free ion. MnF2 is linear with a 6Σg ground state with magnetic parameters in solid neon (assuming g∥=2.002): g⊥=1.994(5), ‖D‖=0.370(3) cm−1, ‖A∥(Mn) ‖=153(6), ‖A⊥(Mn) ‖=124(1), ‖A⊥(F) ‖=19(1) MHz. Comparison of these parameters is made with those obtained earlier from crystalline MnF2 and similar magnetic crystals.