Giant Dielectric Anomaly of a Metal–Organic Perovskite with Four‐Membered Ring Ammonium Cations

Pucker up: A metal–organic perovskite with four-membered-ring azetidinium cations (see structure) exhibited a very broad and unprecedentedly large dielectric peak near 280 K. It is highly possible that the ring-puckering instability of the four-membered-ring ammonium cation plays an essential role in inducing the change of the lattice symmetry and the extraordinarily large dielectric anomaly. 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.