title: Effect of the crystal structure of small precursor particles on the growth of β-NaREF4 (RE = Sm, Eu, Gd, Tb) nanocrystals.
abstract: The origin of the narrow particle size distributions obtained in the oleic acid-based synthesis of hexagonal phase β-NaREF(4) nanocrystals (RE = Sm, Eu, Gd, Tb) has been investigated. Compared to the standard synthesis, the growth conditions were simplified by using small purified particles of either α-NaREF(4) (cubic phase) or β-NaREF(4) (hexagonal phase) as single-source precursors, thereby avoiding the complications arising from the simultaneous presence of molecular educts and intermediately formed small particles. The study shows that α-phase as well as β-phase particles grow by Ostwald-ripening but narrow particle size distributions of the β-NaREF(4) product particles are only obtained when α-phase precursor particles are employed. Since the small particles are also formed as intermediate products in the standard synthesis of β-NaSmF(4), β-NaEuF(4), β-NaGdF(4) and β-NaTbF(4) particles, their crystal phase is an important parameter to obtain a narrow size distribution in these systems.
authors.affiliation: Institute of Chemistry of New Materials, Osnabrück University, Barbarastr.7, 49076 Osnabrück, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Voß
authors.forename: Jörg
authors.initials: J
authors.lastname: Nordmann
authors.forename: Andreas
authors.initials: A
authors.lastname: Uhl
authors.forename: Rajesh
authors.initials: R
authors.lastname: Komban
authors.forename: Markus
authors.initials: M
authors.lastname: Haase
mesh_terms: D003460:Crystallization; D005063:Europium / Q000737:chemistry*; D005459:Fluorides / Q000138:chemical synthesis* / Q000737:chemistry; D005682:Gadolinium / Q000737:chemistry*; D008422:Materials Testing; D046529:Microscopy, Electron, Transmission / Q000379:methods; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D019301:Oleic Acid / Q000737:chemistry; D010316:Particle Size; D012493:Samarium / Q000737:chemistry*; D012964:Sodium / Q000737:chemistry; D013314:Stress, Mechanical; D013696:Temperature; D013725:Terbium / Q000737:chemistry*; D013816:Thermodynamics; D014961:X-Ray Diffraction
chemical_list: D013725:Terbium; D019301:Oleic Acid; D012493:Samarium; D005063:Europium; D012964:Sodium; D005682:Gadolinium; D005459:Fluorides