EPR study of Fe3+ paramagnetic centers in doped triglycine sulphate crystals

Abstract

This paper presents EPR study of Fe3+ in triglycine sulphate doped with Fe3+ crystal. Fe3+ ion is in a high spin stateS = 5/2. EPR signal can be detected only below 200 K. At 4.2 K the EPR spectrum results from three non-equivalent sites of Fe3+ ions. The spin Hamiltonian: H = βBĝS + D[Sz2-(1/3)S(S + 1)] + E(Sx2 - Sy2) has been applied to describe the spectrum. The zero field splitting parameter in this case fulfills the condition: D ≫ hv. An experimental spectrum reflects clearly only two resonance transitions: |±l/2〉 (the lowest Kramers doublet) and | ± 3/2〉 (the middle Kramers doublet). The iron complexes occupy interstitial positions in the crystal with distorted octahedral or tetrahedral co-ordination.