A thermolysis approach to simultaneously achieve crystal phase- and shape-control of ternary M-Fe-O metal oxide nanoparticles

Huang, CC; Chang, CN; Yeh, CS

HERO ID

2571609

Reference Type

Journal Article

Year

2011

Language

English

PMID

21879122

HERO ID 2571609
In Press No
Year 2011
Title A thermolysis approach to simultaneously achieve crystal phase- and shape-control of ternary M-Fe-O metal oxide nanoparticles
Authors Huang, CC; Chang, CN; Yeh, CS
Journal Nanoscale
Volume 3
Issue 10
Page Numbers 4254-4260
Abstract Significant studies have achieved beautiful control in particle size, while the shape- and phase-control synthesis of nanoparticles remains an open challenge. In this study, we have developed a generalized methodology to selectively prepare either NaCl-type (reduced form) or spinel-type ferrite (oxidized form) M-Fe-O (M = Mn, Co) crystallites with high reproducibility. A two-step heating process was able to control formation of two types of crystal phase, either a thermodynamic spinel-type under air or a kinetic-control of NaCl-type (rock salt structure) under Ar in a cubic morphology. On the other hand, the three-step heating procedure in air obtained the spinel-type with a thermodynamic equilibrium octahedral shape exclusively. Either using metal acetates (M(ac)(2)) or metal acetylacetonates (M(acac)(2)) as the starting precursors (M = Mn, Co) can be introduced to prepare NaCl-type (reduced form) or spinel-type ferrite (oxidized form) crystallites with identical experimental parameters, including precursor concentration, reaction temperature, reaction time, and heating rate. The oleic acid molecule, reaction temperature, and heating rate employed in the synthesis were carefully examined and found acting as determined roles behind the reaction processes. Apart from the previous literature reports as shape-directed and/or stabilizing agents, the oleic acid molecule played an additional phase-tuning role.
Doi 10.1039/c1nr10701a
Pmid 21879122
Wosid WOS:000295618200040
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English