Premium
Preparation of Monodisperse ε‐Fe 2 O 3 Nanoparticles by Crystal Structural Transformation
Author(s) -
Nakaya Masafumi,
Nishida Ryo,
Hosoda Natsumi,
Muramatsu Atsushi
Publication year - 2017
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.201700110
Subject(s) - nanoparticle , orthorhombic crystal system , dispersity , materials science , phase (matter) , crystal structure , coercivity , crystal (programming language) , chemical engineering , crystallography , analytical chemistry (journal) , nanotechnology , chemistry , organic chemistry , polymer chemistry , engineering , computer science , programming language , physics , condensed matter physics
Monodisperse iron oxide nanoparticles in the ε‐Fe 2 O 3 phase, which is the rare orthorhombic phase among the four crystal systems of Fe 2 O 3 , are prepared via crystal structural transformation induced by heat treatment of SiO 2 ‐coated monodisperse FeO nanoparticles. The mean diameter of the resulting ε‐Fe 2 O 3 nanoparticles is 41.0 ± 4.2 nm. Compared with the as‐synthesized 40.9 ± 3.8 nm‐FeO nanoparticles, which are used as the precursor, the size and size distribution of the nanoparticles remain almost unchanged after heat treatment. By optimizing the thickness of the SiO 2 shell, coalescence of the nanoparticles during heat treatment can be prevented. XRD measurements do not detect the α‐Fe 2 O 3 phase and γ‐Fe 2 O 3 phase in the obtained sample. The resulting ε‐Fe 2 O 3 nanoparticles exhibit a high coercivity of 23.4 kOe at room temperature.
Accelerating Research
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom
Address
John Eccles HouseRobert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom