Hyperfine structure of the epr spectra of mn⁴⁺ ions in a strong trigonal crystal field

Mn4+-Doped Heterodialkaline Fluorogermanate Red Phosphor with High Quantum Yield and Spectral Luminous Efficacy for Warm-White-Light-Emitting Device Application

“…The reason accounting for the different sets of transitions is that, in the cubic crystal structure, the transitions ± 1 / 2 → ± 3 / 2 experience large broadening, rendering them unobservable. The ESR spectra of Na 2 GeF 6 and CsNaGeF 6 are more complex because a zero-field splitting is introduced with a distorted Mn 4+ environment. , In contrast to Na 2 GeF 6 :Mn 4+ , the less complex spectra and stronger relative intensity of the M S transition − 1 / 2 → + 1 / 2 may account for the weaker ZPL emission in CsNaGeF 6 :Mn 4+ .…”

“…The ESR spectra of Na 2 GeF 6 and CsNaGeF 6 are more complex because a zero-field splitting is introduced with a distorted Mn 4+ environment. 40,41 In contrast to Na 2 GeF 6 :Mn 4+ , the less complex spectra and stronger relative intensity of the M S transition − 1 / 2 → + 1 / 2 may account for the weaker ZPL emission in CsNaGeF 6 :Mn 4+ .…”