Giant isotropic negative thermal expansion in Y-doped samarium monosulfides by intra-atomic charge transfer.

ABSTRACT: Stimulated by strong demand for thermal expansion control from advanced modern industries, various giant negative thermal expansion (NTE) materials have been developed during the last decade. Nevertheless, most such materials exhibit anisotropic thermal expansion in the crystal lattice. Therefore, strains and cracks induced during repeated thermal cycling degrade their performance as thermal-expansion compensators. Here we achieved giant isotropic NTE with volume change exceeding 3%, up to 4.1%, via control of the electronic configuration in Sm atoms of SmS, (4 f)⁶ or (4 f)⁵(5d)¹, by partial replacement of Sm with Y. Contrary to NTE originating from cooperative phenomena such as magnetism, the present NTE attributable to the intra-atomic phenomenon avoids t

SUBMITTER: Takenaka K 

PROVIDER: S-EPMC6333773 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature