Forbidden hyperfine transitions in electron spin resonance of Mn²⁺ in NaCl single crystal

Abstract

Forbidden hyperfine transitions are observed in the electron spin resonance spectrum of divalent Mn⁵⁵ion in NaCl single crystal for a particular associated pair. From the measurements of the M = + ½ → − ½, Δ m = ± 1 transitions the parametersQ' and Q" of the nuclear electric quadrupole part of the spin-Hamiltonian H_o = Q' [I_z ² − 1/3 I (I + 1)] + Q" (I_x ²−I_y ²) are found to be + 1·70 × 10⁻⁴ cm.⁻¹ and +0·16 × 10⁻⁴ cm.⁻¹ respectively.