2016 Summer REU Student Information & Research Abstracts
Name: Liana Alves Undergraduate Institution: Haverford College Major: Chemistry REU Advisor: Dr. Pat Woodward Project Title: Mapping out Phase Diagrams of Halide Double Perovskites Abstract: The synthesis of the double perovskites Cs2AgBiCl6, Cs2AgInCl6, Cs2NaInCl6 from solutionmethods have been analyzed using x-ray diffractions. In order to understand what byproducts arebeing made in the complex synthesis of the double perovskites, multiple ternary phase diagramshave been constructed with each point representing a compound synthesized by either solutionor solid state grinding methods. The ternary phase diagrams vary by halide X=Cl, Br, I and by theM3+ =Bi, Sb, In site with the constant AgX and CsX component. The phase diagrams help organizethe synthesis data for any future research done on lead free halide double perovskites. Multiplesynthesis attempts were made on the Cs2AgBiI6 using different reagents and solvents, but theXRD is not conclusive to declare the perovskite form. The Cl-Bi and Br-Bi are complete phasediagrams, but the I-Bi diagram products indicate the system is not yet thermodynamically stable.Synthesis of AgBiBr4, Cs3BiBr6, AgBi2I7 have no literature cited crystal structure and their x-raycrystallography images show promise for solving their structures.