Fe Te Research Articles

CsCl type ordering in sputtered FeTe alloy films

An CsCl type ordering has been observed in sputter-deposited FeTe alloy films. At a substrate temperature of 200°C, all the tellurium atoms replace iron atoms of the body-centered cubic lattice in an orderly way at the composition up to about 22 at.% Te. A phase transition occurs from a crystalline to amorphous state at the composition limit corresponding to the ordering rearrangement.

Phosphorus–tellurium compounds. Part 3. Cyclopentadienyliron tellurophosphorane complexes: tellurium-bridged iron phosphine compounds?

Cyclopentadienyliron tellurophosphorane cations [Fe(C5H5)(CO)2(TePR3)]+(5; R = Me, Pri, But, NMe2, or morpholino) have been prepared by reaction of [Fe(C5H5)(CO)2(thf)]+(thf = C4H8O) with TePR3. The bonding properties of the Fe–Te–P fragment are discussed using n.m.r. data which indicate π bonding between the iron and tellurium atoms.

Sputtered amorphous Fe–Te films: Structural and electrical studies

Thin films of an iron–tellurium alloy were prepared by rf sputtering and characterized by means of x-ray diffraction and Mössbauer spectroscopy. In an immiscible range in equilibrium composition, tellurium atoms were incorporated into iron, distorting the lattice to some extent. Beyond 14 at. % of Te, an amorphous structure appeared. Judging from the metastable superstructures formed at higher substrate temperatures and the covalent nature in the bonding, the kinetic hindrance against the redistribution of the elements due to the local atomic forces during rapid quenching plays a critical role in the formation of amorphous structure in this alloy. In addition, beyond some intermetallic range around 60 at. % Te, an amorphous phase also exists in the tellurium-rich region. The thermal stability was examined by a differential scanning calorimetry; the electrical resistivity is also discussed.

Synthesis of New Amorphous Metallic Spin Glasses M2SnTe4 (MCr, Mn, Fe, Co): Solvent Induced Metal‐Insulator Transformations

Precipitation of amorphous metallic spin glasses from solution is a novel, potentially general method. By this means, main‐group metal polyanions are oxidized by transition‐metal cations. The example which has been studied in most detail is Fe2SnTe4. This forms immediately as a black precipitate when methanolic solutions of anhydrous FeBr2 and K4SnTe4 are mixed at −20°C. The resistivity of pressed powder samples is low. In the presence of strong donor ligands, the FeTe bonds are selectively cleaved. Solid [Fe(en)2]2SnTe4 (orange) is an insulator.

Mössbauer studies on the FeTe system

Binary compounds FeTex have been prepared with x possessing the values 0.95, 1.2, and 2.0. They crystallise in the tetragonal α, hexagonal δ, and orthorhombic β phases, respectively. Mössbauer spectra are recorded for the three compositions from liquid nitrogen temperature to about 700 K. At room temperature and below, all of them exhibit quadrupole split spectra, and are characteristic of high spin Fe2+ covalently bound to the tellurium atom. At about 420 K, the spectrum of FeTe0.95 collapses into a single line. There is also a large change in the isomer shift versus the 1000/T curve at this temperature. The change is correlated to a variation in the conductivity curve also around this temperature region. Conversion of Fe2+ to Fe3+ explains the above phenomena. Similar changes in the isomer shift are observed at temperatures of 500 and 520 K, and accounted for in the case of FeTe1.2 and FeTe2.0, respectively. Die binären Verbindungen FeTex werden mit x-Werten von 0,95; 1,2 und 2,0 hergestellt und kristallisieren in tetragonaler α-, hexagonaler δ- bzw. rhombischer β-Phase. Mößbauer-spektren werden für die drei Zusammensetzungen zwischen Stickstofftemperatur bis etwa 700 K registriert. Bei Zimmertemperatur und darunter zeigen alle quadrupolaufgespaltene Spektren und sind charakteristisch für “high-spin”-Fe2+, das kovalent an ein Telluratom gebunden ist. Bei etwa 420 K fällt das Spektrum von FeTe0,95 in eine einzelne Linie zusammen. Bei dieser Temperatur ergibt sich auch eine große Änderung der Kurve der isomeren Verschiebung über 1000/T. Diese Änderung ist mit Änderungen der Leitfähigkeitskurve in diesem Temperaturbereich korreliert. Konversion von Fe2+ in Fe3+ erklärt diese Erschei-nungen. Ähnliche Änderungen in der isomeren Verschiebung werden bei Temperaturen von 500 und 520 K beobachtet und für die Fälle von FeTe1,2 bzw. FeTe2,0 diskutiert.

A study on some composition of the FeTe system by Mössbauer spectroscopy

physica status solidi (a)Volume 10, Issue 2 p. K121-K123 Short Note A study on some composition of the FeTe system by Mössbauer spectroscopy V. Fano, V. Fano Laboratorio MASPEC del CNR, ParmaSearch for more papers by this authorI. Ortalli, I. Ortalli Istituto Fisica, Gruppo Nazionale Struttura della Materia, Universitá ParmaSearch for more papers by this author V. Fano, V. Fano Laboratorio MASPEC del CNR, ParmaSearch for more papers by this authorI. Ortalli, I. Ortalli Istituto Fisica, Gruppo Nazionale Struttura della Materia, Universitá ParmaSearch for more papers by this author First published: 16 April 1972 https://doi.org/10.1002/pssa.2210100243Citations: 17AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume10, Issue216 April 1972Pages K121-K123 RelatedInformation

Surface Tension at Elevated Temperatures. IV. Surface Tension of Fe–Se and Fe–Te Alloys

Experimental data are given which show the effect of surface active agents, Se and Te, on the surface tension of liquid iron. The sessile drop method was used. Both seleninm and tellurium decreased the surface tension, however, the effect of tellurium is much less marked. (D.E.B.)