Synthesis and microstructural properties of α-Fe1−xGaxOOH solid solutions

摘要: Abstract Isostructural iron oxyhydroxide α-FeOOH (goethite) and gallium α-GaOOH, as well their solid solutions α-Fe1−xGaxOOH in a whole concentration range (x = 0.00, 0.05, 0.10, 0.15, 0.20, 0.30, 0.50, 0.80 or 1.00) were synthesized by precipitation weakly alkaline medium using an organic alkali tetramethylammonium hydroxide (TMAH) for pH adjustment. Lath-shaped particles common goethite formed media observed all samples containing more Fe than Ga, whereas fairly uniform ellipsoidal characteristic of α-GaOOH Ga Fe. An increased content Ga3+ ions led to decrease the unit-cell size (in line with smaller radius ions). A reduction hyperfine magnetic field collapse room temperature order x > 0.2 found (due dilution lattice brought about replacement Fe3+ diamagnetic shift position (Fe,Ga)–O–H bending bands Fe–O Fe–OH stretching (lattice vibration) towards higher wave numbers strength O–H⋯O hydrogen bond), intensity absorption UV–Vis–NIR spectra ligand transition lower energies increase splitting energy), dehydroxilation stability Ga–OH bond comparison bond) also found.