• Omura, Yuriko
• Suzuki, Yasutaka
• Kawamata, Jun
• Hoshino, Norihisa
• Inoue, Katsuya
• Morita, Hagino
• Akutagawa, Tomoyuki
• Nishihara, Sadafumi

Abstract

<jats:title>Abstract</jats:title><jats:p>We report the development of a molecular ferroelectric material inspired by the hexamethylenetetramine (hmta) non‐centrosymmetric molecular rotator. The bromide salt of diprotonated hmta (hmtaH<jats:sub>2</jats:sub>) crystalized as (hmtaH<jats:sub>2</jats:sub>)(NH<jats:sub>4</jats:sub>)Br<jats:sub>3</jats:sub> in a metal‐free ABX<jats:sub>3</jats:sub> perovskite‐type structure, in which the A and B sites are occupied by hmtaH<jats:sub>2</jats:sub><jats:sup>2+</jats:sup> and ammonium cations, respectively. The compound crystallized in the <jats:italic>P</jats:italic>ma2 polar space group. A distorted polar perovskite structure formed owing to the distortion of {(NH<jats:sub>4</jats:sub>)Br<jats:sub>6</jats:sub>} octahedrons that are stabilized through the formation of NH⋅⋅⋅Br hydrogen bonds and the orientational ordering of positive charges on the non‐centrosymmetric hmtaH<jats:sub>2</jats:sub> molecules. This spontaneous polarization exhibited ferroelectric behavior with a nominally high Curie temperature (&gt;400 K), in which the electrical switching of polarization originates from the rotation of the hmtaH<jats:sub>2</jats:sub> unit.</jats:p>

Topics

• perovskite
• compound
• Hydrogen
• space group
• Curie temperature