Atomic Order and Transferred Hyperfine Field in Co₂TiSn Reexamined by Tin-119 Mössbauer Spectroscopy

Abstract

The tin-119 Mössbauer spectra of Co2TiSn have been measured between 83 and 390 K. In Co2TiSn, which belongs to the L21 type of Heusler alloys, each of the constituent atoms occupies a single cubic crystallographic site. Below the Curie temperature of 371 K, the tin atoms experience a sizeable transferred hyperfine field that increases from 48.0 T at 350 K to 79.5 T at 83 K. At 350 K, the spectrum reveals the presence of both ferromagnetic and paramagnetic regions in Co2TiSn. Their coexistence may result from some titanium-tin site exchange, an exchange that leads to a distribution of tin and titanium in the second near neighbors of the tin atoms and accounts for the large observed spectral line widths. At 390 K, above the Curie temperature, the singlet paramagnetic tin-119 Mössbauer spectrum is also substantially broadened, a broadening, which may result from a distribution of isomer shift and quadrupole splittings due to the distribution of tin and titanium in the second near neighbors of the tin atoms.

Department(s)

Chemistry

Keywords and Phrases

Crystallography; Ferromagnetic Materials; Mössbauer Spectroscopy; Parameter Estimation; Spectrometers; Thickness Measurement; X Ray Diffraction; Curie Temperature; Magnetically Ordered Materials; Tin-119; Cobalt Alloys; Transition Metal Compounds

International Standard Serial Number (ISSN)

0925-8388

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2004 Elsevier, All rights reserved.

Publication Date

01 Sep 2004

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