Mössbauer Line Positions and Hyperfine Interactions in α Iron

Abstract

The 57Fe Mössbauer spectrum of NBS standard reference material 1541 α-iron foil has been determined at 298±2 and 4.2±0.1°K, using a palladium source at 298±2°K. Line positions at 298 and 4.3°K were determined for the calibration of Mössbauer spectrometers. The magnetic splitting, in mm/sec, of the 57Fe ground state and first excited state are g0=(3.9098±0.0008), g1=(2.2342±0.0008) at 298°K and g0=(4.0117±0.0010), g1=(2.2931±0.0010) at 4.3°K. The center shift is − (0.1748±0.0008) mm/sec at 298°K and − (0.0556±0.0012) mm/sec at 4.3°K; the temperature shift is − (0.1192±0.0014) mm/sec. The hyperfine magnetic field is − (330.4±0.3) kOe at 298°K and − (339.0±0.3) kOe at 4.3°K. The 57Fe magnetic moment ratio is μ1/μ0=−1.7145±0.0005. The magnetic moment of the first excited state is μ1=−0.1547±0.0001 nm. The hyperfine magnetic field ratio is H(298°K)/H(4.3°K)=0.9746±0.0001. The electric quadrupole effect in terms of ε, the shift of the ±32 levels, is 4ε=+0.0023±0.0015 mm/sec at 298°K and 4ε=+0.0088±0.0025 mm/sec at 4.3°K. At 298°K, the quadrupole coupling is never between +0.0023±0.0015 mm/sec and −0.0046±0.0030 mm/sec. At 4.3°K, it is never between +0.0088±0.0025 mm/sec and −0.0176±0.0050 mm/sec. The 57Fe Mössbauer transition in palladium is more energetic than in sodium nitroprusside by 0.4361±0.0009 mm/sec.