A Mössbauer Study of the β Phase of Iron–Germanium

1975 ◽  
Vol 53 (21) ◽  
pp. 2428-2437 ◽  
Author(s):  
J. M. Daniels ◽  
F. E. Moore ◽  
S. K. Panda

Measurements have been made of the Mössbauer spectra of 5 samples of the β phase of iron–germanium, covering the full range of composition, Fel+yGe (1/2 ≤ y ≤ 1), of this phase. Spectra were taken for both randomly oriented powders and also powders with the grains oriented with an easy direction of magnetization perpendicular to the plane of the absorber. The spectra resolved into 3 six-line patterns, indicating 3 inequivalent Fe sites. The occupation numbers and canting angles of each site were measured and the spins localized on each site were deduced to be 1/2, 2, and 2. The structure of this phase is discussed in the light of these observations.

1982 ◽  
Vol 60 (11) ◽  
pp. 1564-1572
Author(s):  
J. M. Daniels ◽  
H. Y. Lam ◽  
P. L. Li

57Fe Mössbauer spectra were obtained by scattering in a narrow angle geometry from a face, containing the basal plane, of a single crystal of the hexagonal β phase Fe1.67 Ge. Spectra were also obtained from a source of 57Co diffused into an a–c face of a single crystal of this alloy. In all cases, the spectra were satisfactorily resolved into three six-line patterns, and measurements of the relative intensities of the lines indicate that the antiferromagnetic state has a canted structure with all the spins lying in the basal plane.


1976 ◽  
Vol 54 (18) ◽  
pp. 1850-1853 ◽  
Author(s):  
G. A. Fatséas

A Mössbauer study of iron germanide was published recently in this journal (Daniels, Moore, and Panda). The authors reported that they reproduced, by computer analysis, their Mössbauer spectra in terms of three six-line iron sites, rejecting our earlier results of several FeI and FeII sites identified from a model of statistical (binomial) distribution of vacancies on the iron-site positions (Fatséas, Dormann, and Brossard). We would like, in this paper, to make some remarks and also to present some of our unpublished results for eventual future discussions.


Mineralogia ◽  
2013 ◽  
Vol 44 (1-2) ◽  
pp. 3-12 ◽  
Author(s):  
Kamaleldin M. Hassan ◽  
Julius Dekan

AbstractOlivine basalts from southern Egypt were studied by 57Fe Mössbauer spectroscopy at 297 and 77 K, and by optical microscopy and X-ray diffraction. The 57Fe Mössbauer spectra show three-magnetic sextets, three doublets of ferrous (Fe2+), and a weak ferric (Fe3+) doublet that is attributable to a nanophase oxide (npOx). The magnetic sextets relate to titanomagnetite and the Fe2+ doublets to olivine, pyroxene, and ulvöspinel. Variations in the hyperfine parameters of the various Fe components are attributed to changes in the local crystal chemistry. The intensity of oxidation (Fe3+/ΣFe) in the rocks varies from 20-27% with the oxidized iron largely residing in the titanomagnetite.


Clay Minerals ◽  
1981 ◽  
Vol 16 (3) ◽  
pp. 221-230 ◽  
Author(s):  
A. Kotlicki ◽  
J. Szczyrba ◽  
A. Wiewióra

AbstractFour bands occur in the Mössbauer spectra of pelletal glauconites ranging in age from Cambrian to Oligocene. Components due to Fe3+ in the cis M(2) positions are visible in all the spectra but their shapes depend on the expanding layer content. In the spectrum of the Oligocene glauconite a very well-developed shoulder due to Fe2+ in the trans M(1) positions is observed. In the younger glauconites (15–20% expanding layers) the conventional assignments of the spectra indicate that Fe2+ occupies the trans M(1) positions, the cis M(2) positions being vacant. Conversely, in the Palaeozoic samples (~5% expanding layers) the cis occupancy significantly prevails over trans occupancy.


Nukleonika ◽  
2015 ◽  
Vol 60 (1) ◽  
pp. 7-10 ◽  
Author(s):  
Mieczysław Budzyński ◽  
Virgil C. Constantin ◽  
Ana-Maria J. Popescu ◽  
Zbigniew Surowiec ◽  
Tamara M. Tkachenka ◽  
...  

Abstract The Nd2Fe14B cylindrical magnets were treated with water solutions of alkali, acid, and salt. Mössbauer spectroscopy was applied to study the composition and properties of the surface material of the treated magnets. It is shown that the main phase of the permanent Nd2Fe14B magnet partly decomposes. The released α-Nd at the grain boundaries interacts with water and forms neodymium hydroxide matrix, and the released Fe diffuses into it. The presence of Fe-Nd(OH)3 is reflected in the paramagnet doublet in the Mössbauer spectra of treated neodymium magnets.


1978 ◽  
Vol 56 (18) ◽  
pp. 2417-2421 ◽  
Author(s):  
Jack G. Ballard ◽  
Thomas Birchall ◽  
Ronald J. Gillespie ◽  
Edward Maharajh ◽  
David Tyrer ◽  
...  

Antimony-121 Mössbauer spectra for [Sb2F42+][SbF6−]2 and three compounds containing the [Sb3F14−] ion are reported. The Mössbauer data are discussed in relation to their known structures. Two of the compounds give spectra which, on analysis, give η values of unity.


1981 ◽  
Vol 59 (6) ◽  
pp. 913-917 ◽  
Author(s):  
Nigel S. Dance ◽  
Pablo Dobud ◽  
Colin H. W. Jones

The 125Te Mössbauer spectra of a number of hexahalotellurates have been measured and no significant effects of the size or symmetry of the cation on the Mössbauer parameters were observed. The mixed hexahalotellurates, M2TeX4Y2 (X, Y = Cl, Br, or I), do not exhibit a quadrupole splitting, Δ, and the trends in δ with variation in X and Y are discussed. The pentahalotellurates MTeCl5, MTeBr5, and MTeBr4Cl also yield single line spectra and this is interpreted as evidence of intermolecular bridging. The tetrahaloaryltellurates MArTeX4 and MArTeX3Y (X, Y = Cl, Br, or I) have been studied and the trends in Δ with variation X and Y are consistent with an additive model. The trends in δ are more complex.


Author(s):  
Ahmed D. Al-Rawas ◽  
Abbasher M. Gismelseed ◽  
Subhi Nasir ◽  
Ali A. Yousif ◽  
Mohamed E. Elzain ◽  
...  

A number of meteorites from the desert of Oman, classified as H-chondrites, with known and unknown ages, were studied by using 57Fe Mössbauer spectroscopy to determine their Fe3+-bearing compositions. Mössbauer spectra measured at 78 K were composed of paramagnetic doublets superimposed on magnetic sextets. The doublets are assigned to the silicate minerals olivine and pyroxene and Fe3+ phases. The magnetic sextets in most samples showed the presence of at least three magnetic phases, namely troilite, magnetite and kamacite, which commonly exist in most ordinary chondrites. The relative amounts (area %) of Fe3+ in the known-age meteorites, determined from the Mössbauer spectra, were plotted against their terrestrial ages. The plot was used to estimate the terrestrial ages of meteorites with unknown terrestrial age.


1986 ◽  
Vol 64 (5) ◽  
pp. 987-990 ◽  
Author(s):  
C. H. W. Jones ◽  
R. D. Sharma ◽  
D. Naumann

The 125Te Mössbauer spectra for (CF3)2Te and (C6F5)2Te have been recorded and exhibit significantly larger quadrupole splittings (14.02 and 13.40 mm s−1 respectively) than those of Me2Te (10.5 mm s−1) and Ph2Te (11.0 mm s−1). The dihalides (CF3)2TeX2 and (C66F5)2TeX2 (X = F, Cl,Br) have consistently smaller quadrupole splittings than the dihalides Me2Tex2 and Ph2TeX2. These observations are consistent with the greater electronegativity of the CF3 and C6F5 ligands. The 125Te nmr chemical shifts of (C6F5)Te and its dihalides show a consistent trend to more positive values (increased deshielding) as the electronegativity of the ligands attached to tellurium increases ((C6F5)Te, 297.6 ppm; (C6F5)2TeF2, 1060 ppm). However, for (CF3)2Te and its dihalides a more complex pattern is observed which may be explained by changes in the mean electronic excitation term in the Ramsey paramagnetic shielding term.


1973 ◽  
Vol 51 (3) ◽  
pp. 405-410 ◽  
Author(s):  
P. Vasudev ◽  
C. H. W. Jones

The 57Fe Mössbauer spectra of the cis-Fe(CO)4X2 compounds (X = Cl, Br, I) have been measured and the values of δ (~0.3 mm s−1) and Δ (~0.3 mm s−1) found to differ significantly from those previously reported for Fe(CO)4I2. The Δ values are analyzed in terms of p.q.s. values of the ligands.The photolysis of cyclohexane solutions of Fe(CO)4I2 was studied and no evidence was found in the 57Fe Mössbauer spectra of frozen samples for the previously proposed formation of trans-Fe(CO)4I2.The 129I Mössbauer absorption spectrum of cis-Fe(CO)4129I2 is reported and the parameters found to be δ = +0.11 ± 0.02 mm s−1, e2qQ = −980 ± 10 Mc s−1, η = 0.00 ± 0.02. The parameters are interpreted as evidence of ca. 5% 5s character on the iodine in the Fe—I bond.


Sign in / Sign up

Export Citation Format

Share Document