A handy guide to complex cluster formation in the crystalline model of two-dimensional layered perovskite halide salt

Publication date: Available online 6 August 2019Source: Journal of Physics and Chemistry of SolidsAuthor(s): Beata StaśkiewiczAbstractThe paper presents significantly salient issue in the field of two dimensional halide-based perovskites with diammonium cations on the example of one of their representatives, i.e. compound of chemical formula (NH3)2(CH2)3CdBr4, as one of the important contemporary targets. We have focused our attention on the mechanism of complex cluster formation revealed by dielectric spectroscopy measurements. Dielectric modulus representation obtained for the investigated sample was interpreted within the stochastic scenario of the correlated-clusters scheme. The eye-catching feature of analyzed compound is relaxation response governed by the contribution of two relaxation processes in the high-temperature structural modifications, i.e. Ima2 (phase II) and P21/m (phase III), which showed the generalized Mittag-Leffler two-power-law relaxation pattern, while the room temperature phase Pnma (phase I) is portrayed only by the Cole-Cole relaxation law. Also demonstrated that dielectrically active are all the phase transformations in the analyzed compound. The odd number of carbon atoms in the alkylammonium chains as well as hydrogen and ionic bonding scheme with trans effect affect on the unusual electric behavior and point to complex cluster formation in the analyzed alkylene-diammonium complex. Optical measurements indicate that the investigated material is...
Source: Journal of Physics and Chemistry of Solids - Category: Physics Source Type: research