期刊
ACS NANO
卷 8, 期 8, 页码 8113-8120出版社
AMER CHEMICAL SOC
DOI: 10.1021/nn5022007
关键词
chemical ordering; nanoparticles; Fe-Au; nanomagnetism; thermodynamics
类别
资金
- U.S. Department of Energy EPSCoR State and National Laboratory Partnership Program [DE-SC0001269]
- U.S. Department of Energy (USDOE), Office of Science (OS), Office of Basic Energy Sciences (BES) [DE-AC02-07CH11358]
- USDOE Basic Energy studies, Materials Science and Engineering [DE-FG02-04ER46152]
- US Army Research Office [WF911NF-10-2-0099]
- Nebraska Research Initiative
- NSF-MRI [DMR-0960110]
Formation of chemically ordered compounds of Fe and Au is inhibited in bulk materials due to their limited mutual solubility. However, here we report the formation of chemically ordered L1(2)-type Fe3Au and FeAu3 compounds in Fe-Au sub-10 nm nanoparticles, suggesting that they are equilibrium structures in size-constrained systems. The stability of these L1(2)-ordered Fe3Au and FeAu3 compounds along with a previously discovered L1(0)-ordered FeAu has been explained by a size dependent equilibrium thermodynamic model. Furthermore, the spin ordering of these three compounds has been computed using ab initio first-principle calculations. All ordered compounds exhibit a substantial magnetization at room temperature. The Fe3Au had a high saturation magnetization of about 143.6 emu/g with a ferromagnetic spin structure. The FeAu3 nanoparticles displayed a low saturation magnetization of about 11 emu/g. This suggests a antiferromagnetic spin structure, with the net magnetization arising from uncompensated surface spins. First principle calculations using the Vienna ab initio simulation package (VASP) indicate that ferromagnetic ordering is energetically most stable in Fe3Au, while antiferromagnetic order is predicted in FeAu and FeAu3, consistent with the experimental results.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据