Mills and Chilton groups Molecular magnetic hysteresis at 60 K: Paper in Nature

Dr Conrad Goodwin, a current EPSRC Doctoral Prize Fellow at the School of Chemistry, is first author on a recent paper in Nature from the Mills and Chilton groups.

(Conrad A. P. Goodwin, Fabrizio Ortu, Daniel Reta, Nicholas F. Chilton and David P. Mills, Molecular hysteresis at 60 K in dysprosocenium, Nature2017548, 439, doi:10.1038/nature23447; see the press release here.

Highlighted in Nature News and Views2017548, 400; New ScientistChemistry WorldDigital TrendsNanowerk; and, The Conversation).

The team have isolated an example of the previously elusive dysprosocenium cation and shown that it exhibits magnetic hysteresis, a memory effect, up to 60 K. This eclipses the previous record of 14 K, which was set in 2011. The first single molecule magnet (SMM) was reported in 1993, showing hysteresis up to 4 K, thus molecular hysteresis temperatures had increased by only 10 K in nearly 25 years before this new discovery at Manchester.

SMMs have been lauded as candidates for high density data storage, but to date they have only shown magnetic hysteresis with expensive liquid helium cooling, which is impractical for industrial exploitation. The dysprosocenium complex reported by the team operates up to 60 K, close to the temperature of liquid nitrogen (77 K), and thus nearing the first barrier for commercial applicability.

A combined experimental and pioneering theoretical study shows that magnetic relaxation is due to localised molecular vibrations, particularly involving C–H bonds on the cyclopentadienyl rings, setting new molecular design criteria to realise hysteresis at higher temperatures in the future.

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