Md Minuddin Ph.D. dissertation defense
Thursday, April 7, 2022, at 2:00pm, GN261.
Connection between structure and physical properties of Prussian Blue Analogues
Few Prussian Blue Analogues (PBAs) show negative thermal expansion (NTE), and one of the explanations for NTE is the resonant-unit mode (RUMs). A series of PBAs with chemical formulae, M2[Fe(CN)6].xH2O, where M= Mn, Co, Ni, and Cu and x is the number of water molecules, are prepared using the chemical precipitation method and characterized using Fourier Transform Infrared (FTIR) spectroscopy, Thermogravimetric/Differential Scanning Calorimetry (TGA/DSC), X-ray diffraction (XRD), and inelastic neutron scattering (INS) studies. My results indicate that RUMs are unlikely to be responsible for the negative thermal expansion in this class of materials. All PBAs structure contains water, and, in the literature, it is usually measured from the Thermogravimetric (TGA) analysis. However, density-functional theory (DFT) predicts much lower water content for Ni3[Fe(CN)6]2.xH2O PBAs compared to TGA results. Using a deuterated sample, neutron diffraction and Pair-Distribution-Function (PDF) studies are done to determine the structure of this PBAs, which included determining the location of the water molecules. Besides, a thermal stability study is done for temperatures up to 600oC.
Committee:
Dr. Heinz Nakotte, chair
Dr. Boris Kiefer
Dr. Matthew Sievert
Dr. Meng Zhou
