Iron-based bimagnetic core/shell nanostructures in SiO2: a TEM, MEIS, and energy-resolved XPS analysis
Source abstract
Abstract
Structural, compositional, and chemical changes during the growth of ion beam-synthesised nanoparticles under electron beam annealing (EBA) at 1,000 °C in high vacuum conditions were investigated using medium energy ion scattering, energy-resolved X-ray photoelectron spectroscopy, and transmission electron microscopy. The nanoparticles evolved from <5 to 30 nm diameter Fe-metal (core)/amorphous FexSi33−xOy (shell) structures to single 5–30 nm Fe crystalline nanoparticles sitting on the SiO2 as the annealing time was increased. The stoichiometry of the shell after 60 s EBA at 1,000 °C was found to be (O2)x:Fe14Si19O52 with x between 1 and 7.5 where x increases with increasing depth. This amorphous-shell phase has not been previously reported and a reanalysis of the magnetization data shows that it is ferromagnetic with a magnetic moment of about 1.7 μB per Fe atom even at 300 K. The low-temperature magnetic hysteresis and magneto-optical Kerr-effect hysteresis at room temperature are enhanced when the core/shell nanoparticles are present. A maximum coercive field of about 740 Oe was found with a corresponding Kerr rotation of about 0.04°.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Magnetic properties of thin films · Magnetic Properties and Synthesis of Ferrites · Iron oxide chemistry and applications
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (25)
Show source-provided references
1. Atkinson A, Gardner JW (1981) The diffusion of Fe3+ in amorphous SiO2 and the protective properties of SiO2 layers. Corros Sci 21(1):49–5810.1016/0010-938X(81)90063-9 ↗
2. Barick KC, Varaprasad BSDCS, Bahadur D (2010) Structural and magnetic properties of γ- and ε-Fe2O3 nanoparticles dispersed in silica matrix. J Non-Cryst Solids 356(3):153–15910.1016/j.jnoncrysol.2009.10.001 ↗
3. Betzig E, Trautman JK, Wolfe R, Gyorgy EM, Finn PL, Kryder MH, Chang C-H (1992) Near-field magneto-optics and high density data storage. Appl Phys Lett 61(2):142–14410.1063/1.108198 ↗
4. Cowburn RP (2002) Magnetic nanodots for device applications. J Magn Magn Mater 242–245(Part I):505–51110.1016/S0304-8853(01)01086-1 ↗
5. De G, Tapfer L, Catalano M, Battaglin G, Caccavale F, Gonella F, Mazzoldi P, Haglund RF Jr (1996) Formation of copper and silver nanometer dimension clusters in silica by the sol-gel process. Appl Phys Lett 68(26):382010.1063/1.116628 ↗
6. Dempsey NM, Ranno L, Givord D, Gonzalo J, Serna R, Fei GT, Petford-Long AK, Doole RC, Hole DE (2001) Magnetic behavior of Fe:Al2O3 nanocomposite films produced by pulsed laser deposition. J Appl Phys 90(12):626810.1063/1.1415054 ↗
7. Haverkamp RG, Marshall AT, Cowie BCC (2011) Energy resolved XPS depth profile of (IrO2, RuO2, Sb2O5, SnO2) electrocatalyst powder to reveal core-shell nanoparticle structure. Surf Interface Anal 43(5):847–85510.1002/sia.3644 ↗
8. Johnston-Peck AC, Wang J, Tracy JB (2009) Synthesis and structural and magnetic characterization of Ni(Core)/NiO(Shell) nanoparticles. ACS Nano 3(5):1077–108410.1021/nn900019x ↗
9. Kennedy J, Leveneur J, Takeda Y, Williams GVM, Kupke S, Mitchell DRG, Markwitz A (2011a) Evolution of the structure and magneto-optical properties of ion beam synthesized iron nanoclusters. J Mater Sci 47(3):1127–113410.1007/s10853-011-5849-1 ↗
10. Kennedy J, Leveneur J, Williams GVM, Mitchell D, Markwitz A (2011b) Fabrication of surface magnetic nanoclusters using low energy ion implantation and electron beam. Nanotechnology 22:11560210.1088/0957-4484/22/11/115602 ↗
11. Kimizuka N, Katsura T (1975) Standard free energy of formation of YFeO3, Y3Fe5O12, and a new compound YFe2O4 in the Fe–Fe2O3–Y2O3 system at 1200 °C. J Solid State Chem 13(3):176–18110.1016/0022-4596(75)90116-4 ↗
12. Leveneur J, Kennedy J, Williams GVM, Metson J, Markwitz A (2011a) Large room temperature magnetoresistance in ion beam synthesized surface Fe nanoclusters on SiO2. Appl Phys Lett 98:05311110.1063/1.3553274 ↗
13. Leveneur J, Waterhouse GIN, Kennedy J, Metson JB, Mitchell DRG (2011b) Nucleation and Growth of Fe Nanoparticles in SiO2: a TEM, XPS, and Fe L-edge XANES investigation. J Phys Chem C 20985(43):2097810.1021/jp206357c ↗
14. O’Handley RC (1999) Modern magnetic materials: principles and application. Wiley-Interscience, New York
15. Ong QK, Wei A, Lin X-M (2009) Exchange bias in Fe/Fe3O4 core-shell magnetic nanoparticles mediated by frozen interfacial spins. Phys Rev B 80(13):13441810.1103/PhysRevB.80.134418 ↗
16. Powell CJ, Jablonski A (2001) NIST electron effective-attenuation-length database: Version 1.2. Gaithersburg
17. Ramappa DA, Henley WB (1999) Diffusion of iron in silicon dioxide. J Electrochem Soc 146(10):3773–377710.1149/1.1392548 ↗
18. Ramaswamy V, Haynes TE, White CW, MoberlyChan WJ, Roorda S, Aziz MJ (2005) Synthesis of nearly monodisperse embedded nanoparticles by separating nucleation and growth in ion implantation. Nano Lett 5(2):373–37710.1021/nl048077z ↗
19. Sanchez DF, Luce FP, Fabrim ZE, Sortica MA, Fichtner PFP, Grande PL (2011) Structural characterization of Pb nanoislands in SiO2/Si interface synthesized by ion implantation through MEIS analysis. Surf Sci 605(7–8):654–65810.1016/j.susc.2010.12.011 ↗
20. Skumryev V, Stoyanov S, Zhang Y, Hadjipanayis G, Givord D, Nogués J (2003) Beating the superparamagnetic limit with exchange bias. Nature 423:850–85310.1038/nature01687 ↗
21. Sortica MA, Grande PL, Machado G, Miotti L (2009) Characterization of nanoparticles through medium-energy ion scattering. J Appl Phys 106:11432010.1063/1.3266139 ↗
22. Sun S, Murray CB, Weller D, Folks L, Moser A (2000) Monodisperse FePt nanoparticles and ferromagnetic FePt nanocrystal superlattices. Science 287(5460):1989–199210.1126/science.287.5460.1989 ↗
23. Tikhomirov VK, Chibotaru LF, Saurel D, Gredin P, Mortier M, Moshchalkov VV (2009) Er3+-doped nanoparticles for optical detection of magnetic field. Nano Lett 9(2):721–72410.1021/nl803244v ↗
24. Yuan CL (2010) Room-temperature coercivity of Ni/NiO core/shell nanoparticles fabricated by pulsed laser deposition. J Phys Chem C 114(5):2124–212610.1021/jp911015b ↗
25. Zeng H, Li J, Wang ZL, Liu JP, Sun S (2004) Bimagnetic core/shell FePt/Fe3O4 nanoparticles. Nano Lett 4(1):187–19010.1021/nl035004r ↗