EN
This paper presents EPR study of Fe^{3+} in triglycine sulphate doped with Fe^{3+} crystal. Fe^{3 +} ion is in a high spin state S=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 Fe^{3+} ions. The spin Hamiltonian: H=β BĝS+D[S^2_z-(1/3)S(S+1)]+E(S^2_x-S^2_y) has been applied to describe the spectrum. The zero field splitting parameter in this case fulfills the condition: D≫hν. An experimental spectrum reflects clearly only two resonance transitions: |±1/2ã (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.