Skip to main content Accessibility help
×
Home
Hostname: page-component-55597f9d44-xbgml Total loading time: 0.265 Render date: 2022-08-11T14:36:29.459Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "useRatesEcommerce": false, "useNewApi": true } hasContentIssue true

Iron and Iron-oxide on Silica Nanocomposites Prepared by the Sol-gel Method

Published online by Cambridge University Press:  31 January 2011

G. Ennas*
Affiliation:
Dipartimento di Scienze Chimiche, Università di Cagliari, 09100 Cagliari, Italy
M. F. Casula
Affiliation:
Dipartimento di Scienze Chimiche, Università di Cagliari, 09100 Cagliari, Italy
G. Piccaluga
Affiliation:
Dipartimento di Scienze Chimiche, Università di Cagliari, 09100 Cagliari, Italy
S. Solinas
Affiliation:
Dipartimento di Scienze Chimiche, Università di Cagliari, 09100 Cagliari, Italy
M. P. Morales
Affiliation:
Instituto de Ciencia de Materiales de Madrid, CSIC, 28049, Cantoblanco, Madrid, Spain
C. J. Serna
Affiliation:
Instituto de Ciencia de Materiales de Madrid, CSIC, 28049, Cantoblanco, Madrid, Spain
*
a)Address all correspondence to this author. e-mail: ennas@unica.it
Get access

Abstract

γ–Fe2O3/SiO2 and Fe/SiO2 nanocomposites, with a Fe/Si molar ratio of 0.25, were prepared by the sol-gel method starting from ethanolic solutions of tetraethoxysilane and iron (III) nitrate. After gelation the xerogels were oxidated or reduced. Samples were investigated by transmission electron microscopy, x-ray diffraction, differential scanning calorimetry, and thermogravimetry. Magnetic properties of the samples were investigated at room temperature (RT) and at 77 K. Nanometric particles supported in the silica matrix were obtained in all cases. Bigger particles (10 nm) were obtained in the case of Fe/SiO2 nanocomposites with respect to the γ–Fe2O3/SiO2 samples (5–8 nm). A slight effect of sol dilution on particle size was observed only in the case of γ–Fe2O3/SiO2 nanocomposites. A superparamagnetic behavior was shown at RT only by γ–Fe2O3/SiO2 nanocomposites. Iron-based composites exhibited coercivity values higher than 700 Oe at RT.

Type
Articles
Copyright
Copyright © Materials Research Society 2002

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

D.L. Leslie Pelecky and Rieke, R.D., Chem. Mater. 8, 1770 (1996).Google Scholar
Bentivegna, F., Ferré, J., Nyvlt, M., Jamet, J.P., Imhoff, D., Canva, M., Brun, A., Veillet, P., Visnovsky, S., Chaput, F., and Boilot, J.P., J. Appl. Phys. 83, 7776 (1998).CrossRefGoogle Scholar
Bennemann, K.H. and Kontecky, J., Surf. Sci. 156, 1071 (1985).Google Scholar
Luborsky, F.E., J. Appl. Phys. 32, 1715 (1961).Google Scholar
Gunther, L., Phys. World 2, 28 (1990).CrossRefGoogle Scholar
Keane, M.A., J. Catal. 166, 347 (1997).CrossRefGoogle Scholar
Ziolo, R.F., Giannelis, E.P., Weinstein, B.A., M.P. O’Horo, Ganguly, B.N., Mehrotra, V., Russel, M.W., and Huffman, D.R., Science 257, 219 (1992).CrossRefGoogle Scholar
Dagani, R., Science 254, 1300 (1991).Google Scholar
Dormann, J. and Fiorani, D., Magnetic Properties of Fine Particles (North Holland, Amsterdam, The Netherlands, 1992).Google Scholar
Beke, D.L., Crept. Res. Technol. 33, 1039 (1998).3.0.CO;2-X>CrossRefGoogle Scholar
Michael, R.D., Schull, R.D., Schwartzendruber, L.J., Bennet, L.H., and Watson, R.E., J. Magn. Magn. Mater. 111, 29 (1992).CrossRefGoogle Scholar
Wang, J-P. and Luò, H-L., J. Magn. Magn. Mater. 131, 54 (1994).Google Scholar
Chanéac, C., Tronc, E., and Jolivet, J.P., J. Mater. Chem. 6, 1905 (1996).CrossRefGoogle Scholar
Schull, D., Ritter, J.J., Shapiro, A.J., Schwartzendruber, L.J., and Bennet, L.H., J. Appl. Phys. 67, 4490 (1990).CrossRefGoogle Scholar
Roy, S., Das, D., Chakravorty, D., and Agraval, D.C., J. Appl. Phys. 74, 4746 (1993).CrossRefGoogle Scholar
Gangopadhy, S., Hadjipanayis, G.C., Dale, B., Sorensen, C.M., Klabunde, K.J., Papaefthymiou, V., and Kostikas, A.. Phys. Rev. B 45, 9778 (1992).CrossRefGoogle Scholar
F. del Monte, Morales, M.P., Levy, D., Fernandez, A., Ocana, M., Roig, A., Molins, E., O’Grady, K., and Serna, C.J., Langmuir 13, 3627 (1997).Google Scholar
Ennas, G., Marongiu, G., Piccaluga, G., and Solinas, S., in Interface Controlled Materials, Euromat 99, edited by Ruhle, M. and Gleiter, H., (Wiley-VCH, Weinheim, Germany, 2000), Vol. 9.Google Scholar
Warren, B.E. and Averbach, B.L., J. Appl. Phys. 21, 595 (1950).CrossRefGoogle Scholar
Padella, F., Ennas, G., Enzo, S., and Magini, M., ENEA/TIB Review 43, (1989).Google Scholar
PDF-2 File, JCPDS (International Centre for Diffraction Data, Swarthmore, PA, 1998).Google Scholar
Chanéac, C., Tronc, E., and Jolivet, J.P., J. Mater. Chem. 6, 1905 (1996).CrossRefGoogle Scholar
Chantrell, R.W., Popplewell, J., and Charles, S.W., Physica 86–88B, 1421 (1997).Google Scholar
O’Grady, K. and Bradbury, A., J. Magn. Magn. Mater. 38, 91 (1994).Google Scholar
Moumen, N. and Pileni, M.P., Chem. Mater. 8, 1128 (1996).CrossRefGoogle Scholar
Néel, L., Ann. Geophys. 5, 99 (1949).Google Scholar
Chantrell, R.W., Popplewell, J., and Charles, S.W., IEEE Trans. Magn. 5, 975 (1978).CrossRefGoogle Scholar
Ennas, G., Falqui, A., Piccaluga, G., Solinas, S., Gatteschi, D., Sangregorio, C., and Benedetti, A., Z. Naturforsch. 55a, 58 (2000).Google Scholar
Chen, C., Kitakami, O., and Shimada, Y., J. Appl. Phys. 84, 2184 (1998).CrossRefGoogle Scholar
Stoner, E.C. and Wolfart, E.P., Proc. Phys. Soc. A 240, 540 (1948).Google Scholar
Veintemillas-Verdaguer, S., Montero, M.I.. Serna, C.J., Roig, A., Casas, L., Martinez, B., and Sandiumenge, F., Chem. Mater. 11, 3058 (1999).Google Scholar
Linderoth, S., Hendricksen, P.V., Bødker, F., Wells, S., Davies, K., Charles, S.W., and Mørup, S., J. Appl. Phys. 75, 6583 (1994).CrossRefGoogle Scholar

Save article to Kindle

To save this article to your Kindle, first ensure coreplatform@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Iron and Iron-oxide on Silica Nanocomposites Prepared by the Sol-gel Method
Available formats
×

Save article to Dropbox

To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.

Iron and Iron-oxide on Silica Nanocomposites Prepared by the Sol-gel Method
Available formats
×

Save article to Google Drive

To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.

Iron and Iron-oxide on Silica Nanocomposites Prepared by the Sol-gel Method
Available formats
×
×

Reply to: Submit a response

Please enter your response.

Your details

Please enter a valid email address.

Conflicting interests

Do you have any conflicting interests? *