Nanoscale Structural Heterogeneity in Ni-rich Half-Heusler TiNiSn

Published

October 28, 2014

Author(s)

Jason E. Douglas, Philip A. Chater, Craig Brown, Tresa M. Pollock, Ram Seshadri

Abstract

The structural implications of excess Ni in the TiNiSn half-Heusler compound are examined through a combination of synchrotron x-ray and neutron scattering studies, in conjunction with first principles density functional theory calculations on supercells. Despite the phase diagram suggesting that TiNiSn is a line compound with no solid solution, for small x in TiNi_1+xSn there is indeed an appearance - from careful analysis of the scattering- of some solubility, with the excess Ni occupying the interstitial tetrahedral site in the half-Heusler structure. The analysis performed here would point to th excess Ni not being statistically distributed, but rather occurring as coherent nanoclusters. First principles calculations of energetics, carried out using supercells, support a scenario of Ni interstitials clustering, rather than a statistical distribution.

Citation

Journal of Applied Physics

Volume

116

Issue

16

Pub Type

Journals

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Keywords

neutron diffraction, half-heusler, nanoscale, X-ray, structure

Citation

Douglas, J. , Chater, P. , Brown, C. , Pollock, T. and Seshadri, R. (2014), Nanoscale Structural Heterogeneity in Ni-rich Half-Heusler TiNiSn, Journal of Applied Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=917222 (Accessed December 14, 2024)