RMC-8(+1) Conference, Budapest

Cd(CN)2: negative thermal expansion in a structural spin-ice

22 Sept 2023, 09:00

40m

room 103 (Central European University, CEU Nador 15 Campus (Budapest, Hungary))

Talks Fr1

Speaker

Andrew Goodwin (norganic Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, UK)

Description

Cadmium cyanide exhibits the strongest persistent isotropic negative thermal expansion (NTE) effect of all known materials [1,2]. Structural studies of the material are complicated by a combination of extreme x-ray sensitivity [2], the prohibitively large neutron absorption cross-section of natural-abundance cadmium, and the presence of cyanide orientational disorder [3], which is temperature dependent [4]. This talk will summarise some of our recent neutron scattering measurements of 114Cd(CN)2, which are providing insight into the NTE mechanism in Cd(CN)2. Our analysis includes the use of reverse Monte Carlo refinements of neutron total scattering data.

[1] Coates & Goodwin, Mater. Horiz. 6, 211 (2018)
[2] Coates et al., Dalton Trans. 47, 7263 (2018)
[3] Goodwin & Kepert, Phys. Rev. B 71, 140301 (2005)
[4] Coates et al., Nature Comms. 12, 2272 (2021)