TY - JOUR
T1 - Gold-coated cementite nanoparticles
T2 - An oxidation-resistant alternative to α-Iron
AU - Shultz, Michael D.
AU - Calvin, Scott
AU - Fernando Gonzalez-Jimenez, Gonzalez-Jimenez
AU - Mujica, Vladimiro
AU - Alleluia, Blaine C.
AU - Carpenter, Everett E.
PY - 2009/12/8
Y1 - 2009/12/8
N2 - Iron-based nanoparticles are desirable for many applications because of their magnetic properties and inherent biocompatibility. Metallic iron, or α-Fe, is the most sought after because of its high saturation magnetization (up to 220 emu/g). This magnetization in iron nanoparticles is difficult to reach or maintain because of the ease of oxidation, which greatly reduces the magnetization values (90 emu/g or less). Here, we report the synthesis of an iron-based nanoparticle comprising a magnetic cementite core (Fe3C) that is more oxidation-resistant than α-Fe, an oxide layer, and a gold coating for passivation and easy functionalization. The nanoparticle structure was confirmed via X-ray absorption fine structure and Mössbauer experiments, and morphology was confirmed using transmission electron microscopy. Magnetic characterization yielded a saturation magnetization of 110 emu/g, thus demonstrating cementite as more stable alternative to α-Fe with higher magnetic moments than the iron oxides.
AB - Iron-based nanoparticles are desirable for many applications because of their magnetic properties and inherent biocompatibility. Metallic iron, or α-Fe, is the most sought after because of its high saturation magnetization (up to 220 emu/g). This magnetization in iron nanoparticles is difficult to reach or maintain because of the ease of oxidation, which greatly reduces the magnetization values (90 emu/g or less). Here, we report the synthesis of an iron-based nanoparticle comprising a magnetic cementite core (Fe3C) that is more oxidation-resistant than α-Fe, an oxide layer, and a gold coating for passivation and easy functionalization. The nanoparticle structure was confirmed via X-ray absorption fine structure and Mössbauer experiments, and morphology was confirmed using transmission electron microscopy. Magnetic characterization yielded a saturation magnetization of 110 emu/g, thus demonstrating cementite as more stable alternative to α-Fe with higher magnetic moments than the iron oxides.
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U2 - 10.1021/cm901708v
DO - 10.1021/cm901708v
M3 - Article
AN - SCOPUS:72949088854
VL - 21
SP - 5594
EP - 5600
JO - Chemistry of Materials
JF - Chemistry of Materials
SN - 0897-4756
IS - 23
ER -