Principles of melting in hybrid organic-inorganic perovskite and polymorphic ABX3 structures

Four novel dicyanamide-containing hybrid organic-inorganic ABX(3) structures are reported, and the thermal behaviour of a series of nine perovskite and non-perovskite [AB(N(CN)(2))(3)] (A = (C3H7)(4)N, (C4H9)(4)N, (C5H11)(4)N; B = Co, Fe, Mn) is analyzed. Structure-property relationships are investigated by varying both A-site organic and B-site transition metal cations. In particular, increasing the size of the A-site cation from (C3H7)(4)N -> (C4H9)(4)N -> (C5H11)(4)N was observed to result in a decrease in T-m through an increase in Delta S-f. Consistent trends in T-m with metal replacement are observed with each A-site cation, with Co < Fe < Mn. The majority of the melts formed were found to recrystallise partially upon cooling, though glasses could be formed through a small degree of organic linker decomposition. Total scattering methods are used to provide a greater understanding of the melting mechanism.

Automated summary

Four novel hybrid organic-inorganic structures containing dicyanamide are reported, and the thermal behavior of nine different perovskite and non-perovskite compounds is analyzed. The relationship between structure and properties is investigated by varying the organic and transition metal cations. It is observed that increasing the size of the organic cation leads to a decrease in melting point and an increase in entropy change. The melting behavior is consistent with different metal replacements, with Co < Fe < Mn. Most of the melts partially recrystallize upon cooling, but glasses can be formed by decomposing a small amount of organic linker.