Table 2. Parameters Obtained from Fitting ⁵⁷Fe Mössbauer Data of Products from Reaction between Fe₃O₄ and NaNH₂^a.

sample	site	δ (mm s–1)	Δ (mm s–1)	Γ (mm s–1)	fraction (%)	assignment	approximate composition	average formal Fe oxidation state
170 °C/24 h	S1	0.13		0.18	14	γ″-FeN	FeNx	3.00
	D1	0.43	0.30	0.16	30	ε-Fe2+xN Fe(III)	Fe2.38N	1.26
	D2	0.25	0.46	0.19	26	ε-Fe2+xN Fe(II)	Fe2.38N
	D3	0.27	0.83	0.17	29	FeO1–xNx	FeO0.20N0.80	2.80
170 °C/96 h	S1	0.16		0.14	8	γ″-FeN	FeNx	3.00
	D1	0.44	0.29	0.18	31	ε-Fe2+xN Fe(III)	Fe2.38N	1.26
	D2	0.25	0.46	0.18	28	ε-Fe2+xN Fe(II)	Fe2.38N
	D3	0.28	0.84	0.20	33	FeO1–xNx	FeO0.25N0.75	2.75
190 °C/24 h	S1	0.16		0.16	12	γ″-FeN	FeNx	3.00
	D1	0.45	0.28	0.17	26	ε-Fe2+xN Fe(III)	Fe2.38N	1.26
	D2	0.26	0.48	0.17	23	ε-Fe2+xN Fe(II)	Fe2.38N
	D3	0.30	0.92	0.24	39	FeO1–xNx	FeO0.35N0.65	2.65

^aδ – Isomer Shift, Δ – Quadrupole Splitting, Γ – Half-Width Full Max. Δ is given relative to metallic Fe at room temperature. Estimated precision on δ, Δ, and Γ is 0.02 mm s^–1 and 2% on the site fraction. Site assignment for each spectral component is indicated.