Details

Autor(en) / Beteiligte

• Occhialini, Connor A.
• Handunkanda, Sahan U.
• Said, Ayman
• Trivedi, Sudhir
• Guzmán-Verri, G. G.
• Hancock, Jason N.

Titel

Negative thermal expansion near two structural quantum phase transitions

Ist Teil von

• Physical review materials, 2017-12, Vol.1 (7), Article 070603

Ort / Verlag

United States: American Physical Society (APS)

Erscheinungsjahr

2017

Quelle

American Physical Society Journals

Beschreibungen/Notizen

• Recent experimental work has revealed that the unusually strong, isotropic structural negative thermal expansion in cubic perovskite ionic insulator ScF3 occurs in excited states above a ground state tuned very near a structural quantum phase transition, posing a question of fundamental interest as to whether this special circumstance is related to the anomalous behavior. To test this hypothesis, we report an elastic and inelastic x-ray scattering study of a second system Hg2I2 also tuned near a structural quantum phase transition while retaining stoichiometric composition and high crystallinity. We find similar behavior and significant negative thermal expansion below 100 K for dimensions along the body-centered-tetragonal c axis, bolstering the connection between negative thermal expansion and zero-temperature structural transitions. As a result, we identify the common traits between these systems and propose a set of materials design principles that can guide discovery of newmaterials exhibiting negative thermal expansion