Giant Negative Thermal Expansion in the Iron Perovskite SrCu₃Fe₄O₁₂

Abstract

Big and cold: Strong internal compression of the Sr ion in the novel perovskite SrCu3Fe4O12 (see structure) leads to giant negative thermal expansion (NTE) between 170 and 270 K. Mössbauer spectroscopy shows charge disproportionation of FeIV to FeIII and FeV below 200 K. Thus, the isoelectric substitution of the A-site cation can induce a drastic change of the structural and electronic properties in ACu3Fe4O12 perovskites. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.