title: Hydrothermal synthesis and near in situ analysis of NiFe2O4 nanoparticles.
abstract: The hydrothermal synthesis (HS) of NiFe2O4 nanoparticles (NPs) has been investigated using a novel valve-assisted pressure autoclave. This approach has facilitated the rapid quenching of hydrothermal suspensions into liquid nitrogen, providing 'snapshots' representative of the near in situ physical state of the synthesis reaction products as a function of known temperature. The acquired samples were examined using complementary characterisation techniques of transmission electron microscopy and X-ray diffractometry (XRD). The HS of NiFe2O4 NPs (< 25 nm) at pH - 8 proceeded through the formation and dissolution of intermediate amorphous Fe(OH)3 and FeNi3Cl2(OH)8 x H2O sheets with increasing reaction temperature. The near in situ nature of the HS suspension resulted in the formation of NaCI by-product during drying in advance of XRD investigation, not during the HS process.
authors: Division of Materials, Mechanics and Structures, Department of Mechanical, Materials and Manufacturing Engineering, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors: Trevor P
authors: TP
authors: Almeida
authors: Mike
authors: M
authors: Fay
authors: Yanqiu
authors: Y
authors: Zhu
authors: Paul D
authors: PD
authors: Brown
mesh_terms: D003460:Crystallization / Q000379:methods*; D005290:Ferric Compounds / Q000737:chemistry*; D006358:Hot Temperature; D057446:Hydrodynamics; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D008968:Molecular Conformation; D009532:Nickel / Q000737:chemistry*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D005290:Ferric Compounds; D046911:Macromolecular Substances; C550717:nickel ferrite; D009532:Nickel