Colossal negative thermal expansion with an extended temperature interval covering room temperature in fine-powdered Mn0.98CoGe
Colossal negative thermal expansion with an extended temperature interval covering room temperature in fine-powdered Mn0.98CoGe
复制标题
细粉 Mn0.98CoGe 中具有巨大的负热膨胀，温度区间覆盖室温
DOI：
10.1063/1.4972234
复制
发表时间：
2016-12-12
影响因子：
4
通讯作者：
Sun, Yuping
中科院分区：
文献类型：
--
作者：
Lin, Jianchao;Tong, Peng;Sun, Yuping
MnM'X (M' = Co, Ni; X = Ge, Si, etc.) alloys usually present a large volumetric change during the Martensitic (MA) transformation. This offers a great opportunity for exploring new negative thermal expansion (NTE) materials if the temperature interval of NTE can be extended. Here, we report colossal NTE in fine-powdered Mn0.98CoGe prepared by repeated thermal cycling (TC) through the MA transition or ball milling. Both treatments can expand the MA transformation, and thus broaden the NTE temperature window (Delta T). For the powders that have gone through TC for ten times, Delta T reaches 90K (309 K-399 K), and the linear expansion coefficient (alpha(L)) is about -141 ppm/K, which rank among the largest values of colossal NTE materials. The difference between two kinds of treatments and the possible mechanisms of the extended MA transformation window are discussed based on the introduced strain. Published by AIP Publishing.
