Restoration of the third law in spin ice thin films

Journal article

A characteristic feature of spin ice is its apparent violation of the third law of thermodynamics. This leads to a number of interesting properties including the emergence of an effective vacuum for magnetic monopoles and their currents – magnetricity. Here we add a new dimension to the experimental study of spin ice by fabricating thin epitaxial films of Dy2Ti2O7, varying between 5 and 60 monolayers on an inert substrate. The films show the distinctive characteristics of spin ice at temperatures >2 K, but at lower temperature we find evidence of a zero entropy state. This restoration of the third law in spin ice thin films is consistent with a predicted strain-induced ordering of a very unusual type, previously discussed for analogous electrical systems. Our results show how the physics of frustrated pyrochlore magnets such as spin ice may be significantly modified in thin-film samples.

Authors: Bovo, L; Moya, X; Prabhakaran, D; Soh, Y; Boothroyd, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Springer Nature
• Journal: Nature Communications
• Volume: 5
• Article number: 3439
• Publication date: 2014-03-12
• Acceptance date: 2014-02-12
• DOI: 10.1038/ncomms4439
• EISSN: 2041-1723
• Language: English
• Keywords: FFR