CH3NH3PbI3perovskites: Ferroelasticity revealed

CH3NH3PbI3 perovskites: Ferroelasticity revealed

Ferroelectricity has been proposed as a plausible mechanism to explain the high photovoltaic conversion efficiency in organic-inorganic perovskites; however, convincing experimental evidence in support of this hypothesis is still missing. Identifying and distinguishing ferroelectricity from other properties, such as piezoelectricity, ferroelasticity, etc., is typically nontrivial because these ...

Ferroelasticity and domain physics in two-dimensional transition metal dichalcogenide monolayers

Monolayers of transition metal dichalcogenides can exist in several structural polymorphs, including 2H, 1T and 1T'. The low-symmetry 1T' phase has three orientation variants, resulting from the three equivalent directions of Peierls distortion in the parental 1T phase. Using first-principles calculations, we predict that mechanical strain can switch the relative thermodynamic stability between...

First-principles study of structural instabilities in halide-based perovskites: Competition between ferroelectricity and ferroelasticity.

Genetic diversity of Iranian melon cultigens revealed by AFLP markers

Iran is a part of the secondary centre of origin of melons, and therefore, there is a wealth of genetic variation of these species in this country. The Amplified Fragment Length Polymorphism (AFLP) marker was applied to investigate the genetic variations among five major Iranian melon cultigens (Cucumis melo) and ‘Ananasi’ as a general well-known cultivar. Ten primer pairs were used on 90 indiv...

Twinning ferroelasticity facilitated by the partial flipping of phenyl rings in single crystals of 4,4′-dicarboxydiphenyl ether

Evidence of ferroelasticity in a non-planar organic molecular crystal is presented for 4,4'-dicarboxydiphenyl ether. Ferroelasticity has been demonstrated by the micro- and macroscopic mechanical characterization of single crystals, including recording of a full hysteretic stress-strain cycle. The underlying mechanism involves the partial flipping of phenyl rings.