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6876141 
Journal Article 
Good comprehensive performance of Laves phase Hf1-xTaxFe2 as negative thermal expansion materials 
Li, LF; Yang, C; Zhu, XB; Song, WH; Sun, YP; Tong, P; Zou, YM; Tong, W; Jiang, WB; Jiang, Y; Zhang, XK; Lin, JC; Wang, M; , 
2018 
Yes 
Acta Materialia
ISSN: 1359-6454 
PERGAMON-ELSEVIER SCIENCE LTD 
OXFORD 
258-265 
WOS:000449134100023 
Negative thermal expansion (NTE) materials can compensate for the normal positive thermal expansion (PTE) of most materials, and thus have great potential applications. Itinerant magnetic Laves phase compounds Hf1-xTaxFe2 with x similar to 0.16-0.22 exhibit an abrupt volume shrink as large as Delta V/V similar to 1% at the ferromagnetic (FM) to antiferromagnetic phase transition. Here we report that by reducing the Ta concentration the sharp volume change was gradually modified to a continuous one and moved to room temperature. NTE was optimized in x = 0.13, showing a linear NTE coefficient as large as - 16.3 ppm/K over a broad window of 105 K (222 K - 327 K). As revealed by Electron Spin Resonance, the broadened NTE window is closely coupled with the asynchronous FM orderings of Fe moments at 6h and 2a Fe sites. In addition to good mechanical properties (i.e., Young's modulus, compressive strength and Vickers hardness), their thermal and electrical conductivities are superior to other metallic NTE materials, suggesting their wide applications as PTE compensators. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.