Magnetic properties of nanometer-scale ion particles generated by iron atom clustering in cold pentane

Journal Article · · Journal of Physical Chemistry; (USA)

OSTI ID:6726139

Kernizan, C F; Klabunde, K J; Sorensen, C M; Hadjipanayis, G C ^[1]

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1. Kansas State Univ., Manhattan (USA)

Nanometer-scale iron particles have been prepared by iron atom clustering in cold pentane. Particle growth was terminated by adsorption of oleic acid, yielding air-stable particles ranging in size from 2 to 12 nm, that were amorphous according to XRD analysis. TEM analysis showed that the larger particles were prolate spheroids and the smaller ones were spherical. The original sample had a room-temperature saturation magnetization of M{sub s} = 12.3 emu/g and a coercivity of H{sub c} = 60 Oe. Following heat treatment with argon, the XRD results showed the following reaction scheme: oxidation to Fe{sub 3}O{sub 4} at 360{degree}C and reduction to {alpha}-Fe at 520{degree}C (processes apparently due to adsorbed oleic acid). For the 520{degree}C treated sample, the room-temperature saturation magnetization and coercivity were M{sub s} = 200 emu/g and H{sub c} = 20 Oe, respectively. By pentane washing of the as-prepared sample, the smaller particles could be separated by filtration, leaving the larger 8-12-nm particles on the filter. This powdered sample trapped on the filter had M{sub s} = 54.9 emu/g and H{sub c} = 60 Oe. Heat treatment also caused oxidation to Fe{sub 3}O{sub 4} at 360{degree}C and an incomplete reduction to {alpha}-Fe and FeO at 520{degree}C. For the 520{degree}C treated sample, the recorded room-temperature saturation magnetization and coercivity were M{sub s} = 123.6 emu/g and H{sub c} = 20 Oe, respectively.

• OSTI ID: 6726139
• Journal Information: Journal of Physical Chemistry; (USA), Vol. 2:1; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
IRON COMPOUNDS
SYNTHESIS
DATA ANALYSIS
EXPERIMENTAL DATA
MAGNETIC PROPERTIES
MEASURING INSTRUMENTS
MEASURING METHODS
TRANSMISSION ELECTRON MICROSCOPY
DATA
ELECTRON MICROSCOPY
INFORMATION
MICROSCOPY
NUMERICAL DATA
PHYSICAL PROPERTIES
TRANSITION ELEMENT COMPOUNDS
360101* - Metals & Alloys- Preparation & Fabrication
400201 - Chemical & Physicochemical Properties