Origin of Magnetism in Hydrothermally Aged 2-Line Ferrihydrite Suspensions

Cao, Liang1,2; Jiang, Zhao-Xia3; Du, Yong-Hua4; Yin, Xin-Mao5,6; Xi, Shi-Bo4; Wen, Wen1; Roberts, Andrew P.7; Wee, Andrew T. S.5; Xiong, Yi-Min2; Liu, Qing-Song8,9; Gao, Xing-Yu1

2017-03-07

10.1021/acs.est.6b04716

ENVIRONMENTAL SCIENCE & TECHNOLOGY   影响因子和分区

0013-936X

1520-5851

As an iron oxyhydroxide, nanosized ferrihydrite (Fh) is important in Earth science, biology, and industrial applications. However, its basic structure and origin of its magnetism have long been debated. We integrate synchrotron-based techniques to explore the chemical structures of 2-line ferrihydrite and to determine the origin of its magnetism during hydrothermal aging in air. Our results demonstrate that both the magnetism and X-ray magnetic circular dichroism (XMCD) signal of 2-line ferrihydrite are enhanced with aging time, and that XMCD spectral patterns resemble that of maghemite (gamma-Fe2O3) rather than magnetite (Fe3O4). Fe L-edge and K-edge X-ray absorption spectroscopy (XAS) further indicate formation of both maghemite and hematite (alpha-Fe2O3) with increasing concentrations with longer hydrothermal aging time. Thus, magnetic enhancement with longer hydrothermal aging time is attributed to increasing maghemite concentration instead of a magnetically ordered ferrihydrite as previously reported. Moreover, L-edge and K-edge XAS spectra with different probing depths yield different ratios of these Fe oxides, which suggest the formation of a core (ferrihydrite-rich)-shell (with a mixture of both allotropes; alpha-Fe2O3 and gamma-Fe2O3) structure during hydrothermal aging. Our results provide insights into the chemical evolution of 2-line ferrihydrite that reveal unambiguously the origin of its magnetism.

SCI ; EI

英语

NI期刊 ; NI期刊 ; NI论文

通讯

Australian Research Council[DP120103952]

Engineering ; Environmental Sciences & Ecology

Engineering, Environmental ; Environmental Sciences

WOS:000395963800020

AMER CHEMICAL SOC

20172403766473

Biology ; Dichroism ; Gamma rays ; Hematite ; Magnetite ; X ray absorption spectroscopy

Biology:461.9 ; Minerals:482.2 ; Magnetism: Basic Concepts and Phenomena:701.2 ; Light/Optics:741.1 ; Atomic and Molecular Physics:931.3

ENVIRONMENT/ECOLOGY

Web of Science

1.Chinese Acad Sci, Shanghai Inst Appl Phys, POB 800-204, Shanghai 201800, Peoples R China
2.Chinese Acad Sci, High Magnet Field Lab, 350 Shushanhu Rd, Hefei 230031, Anhui, Peoples R China
3.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, 19 Beitucheng Western Rd, Beijing 100029, Peoples R China
4.ASTAR, Inst Chem & Engn Sci, 1 Pesek Rd, Jurong Isl 627833, Singapore
5.Natl Univ Singapore, Dept Phys, 2 Sci Dr 3, Singapore 117542, Singapore
6.Shenzhen Univ, Key Lab Optoelect Devices & Syst, SZU NUS Collaborat Innovat Ctr Optoelect Sci & Te, Minist Educ & Guangdong Prov, Shenzhen 518060, Peoples R China
7.Australian Natl Univ, Res Sch Earth Sci, 142 Mills Rd, Canberra, ACT 2601, Australia
8.Southern Univ Sci & Technol China, Dept Marine Sci & Engn, Shenzhen 518055, Peoples R China
9.Qingdao Natl Oceanog Lab Sci & Technol, Lab Marine Geol, Qingdao 266071, Peoples R China

Cao, Liang,Jiang, Zhao-Xia,Du, Yong-Hua,et al. Origin of Magnetism in Hydrothermally Aged 2-Line Ferrihydrite Suspensions[J]. ENVIRONMENTAL SCIENCE & TECHNOLOGY,2017,51(5):2643-2651.

Cao, Liang.,Jiang, Zhao-Xia.,Du, Yong-Hua.,Yin, Xin-Mao.,Xi, Shi-Bo.,...&Gao, Xing-Yu.(2017).Origin of Magnetism in Hydrothermally Aged 2-Line Ferrihydrite Suspensions.ENVIRONMENTAL SCIENCE & TECHNOLOGY,51(5),2643-2651.

Cao, Liang,et al."Origin of Magnetism in Hydrothermally Aged 2-Line Ferrihydrite Suspensions".ENVIRONMENTAL SCIENCE & TECHNOLOGY 51.5(2017):2643-2651.