Control of multipolar and orbital order in perovskite-like [C(NH2)3]CuxCd1–x(HCOO)3 metal–organic frameworks

Journal article

We study the compositional dependence of molecular orientation (multipolar) and orbital (quadrupolar) order in the family of perovskite-like metal–organic frameworks [C(NH2)3]CuxCd1–x(HCOO)3. On increasing the fraction x of Jahn-Teller-active Cu2+, we observe first an orbital disorder/order transition and then a multipolar reorientation transition, each occurring at distinct critical compositions xo = 0.45(5) and xm = 0.55(5). We attribute these transitions to a combination of size, charge distribution, and percolation effects. The transitions we observe establish the accessibility in for-mate perovskites of novel structural degrees of freedom beyond the familiar dipolar terms responsible for (an-ti)ferroelectric order. We discuss the symmetry implica-tions of cooperative quadrupolar and multipolar states for the design of relaxor-like hybrid perovskites.

Authors: Goodwin, A; Evans, N; Thygesen, P; Boström, H; Reynolds, E

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Chemical Society
• Journal: Journal of the American Chemical Society
• Volume: 138
• Issue: 30
• Pages: 9393–9396
• Publication date: 2016-07-14
• Acceptance date: 2016-07-14
• DOI: 10.1021/jacs.6b05208
• EISSN: 1520-5126
• ISSN: 0002-7863