Transition metal impurity effect on charge and spin density in iron: Ab initio calculations and comparison with Mössbauer data

Abstract

Short title: Transition metal impurity effect on charge and spin density in iron AbstractDensity functional theory was applied to study influence of the isolated impurity located on the regular site of the α-Fe crystal on the charge and spin density (hyperfine interactions) on the iron nucleus. Calculations were performed by using both pseudopotential and the full potential methods. The scalar relativistic approximation was applied. Perturbations of the charge and spin density on iron were calculated for all d impurities soluble in iron and additionally for Ga impurity. It was found that impurities have measurable effect on the iron charge and spin density up to the second or third coordination shell depending on the impurity. Hyperfine parameters of iron adjacent to the impurity are affected by two intermixed physical mechanisms, i.e., the volume mismatch due to the impurity and electron band mixing caused by the electronic configuration of the impurity outer shells. Some correlations between ab initio calculations and Mössbauer experimental results are discussed. A table is provided with the parameters allowing calculate Mössbauer spectrum of the binary iron alloy with d impurity or Ga. On the other hand, provided parameters allow extraction from the Mössbauer data information about impurity concentration and eventual order.

A Study of Thermodynamic Properties of Dilute Fe-Au Alloys by the 57Fe Mössbauer Spectroscopy

“…They are similar to corresponding data given in the literature [22] and simultaneously they are at variance with the theoretical calculations based on density functional theory (DFT) [24]. (4) 0.690(13) 0.0058(5) 0.0010(2) 0.023 33.000(3) 0.688 (11) 0.0101(6) 0.0055(6) 0.034 32.850 (5) 0.620(16) 0.0081(6) 0.0017(4) 0.048 32.810 (7) 0.625(14) 0.0093(9) 0.0012 (5) …”

Interactions between osmium atoms dissolved in iron observed by the 57Fe Mössbauer spectroscopy

“…[16] one can fi nd that for the Fe 0.985 Os 0.015 alloy B 1 = −3.60(3) T, B 2 < 0.5 T and IS 1 = −0.017(2) mm/s. In much recent work [18], it was found that the nearest neighbor single Os impurity reduces hyperfi ne magnetic fi eld on the iron nucleus by 3.97 T, while the second neighbor single Os impurity decreases this fi eld by 1.11 T. At the same time theoretical calculations based on density functional theory (DFT) give results which are different from the experimental ones; according to the calculations B 1 = −2.70 T, B 2 = −0.57 T, B 3 = 0.38 T, IS 1 = −0.010 mm/s, IS 2 = 0.033 mm/s and IS 3 = 0.004 mm/s [19].…”

Hyperfine interactions and some thermomagnetic properties of amorphous FeZr(Cr)NbBCu alloys

“…The Mössbauer spectrum of the sample after substitution 6% at Fe by Cr atoms only slightly changes at both room and nitrogen temperatures [12]. After the annealing at 700 K, the isomer shift decreases up to -0.101(2) mm/s and remains constant after annealing at 750 K. It could be caused by the decrease of distances between Fe and Cr atoms or/and the increase of Cr concentration.…”