Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-11-29T19:09:32.617Z Has data issue: false hasContentIssue false

Structural, morphological, and magnetic study of nanocrystalline cobalt-copper powders synthesized by the polyol process

Published online by Cambridge University Press:  03 March 2011

G.M. Chow*
Affiliation:
Laboratory for Molecular Interfacial Interactions, Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375
L.K. Kurihara
Affiliation:
Laboratory for Molecular Interfacial Interactions, Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375
K.M. Kemner
Affiliation:
Condensed Matter and Radiation Division, Naval Research Laboratory, Washington, DC 20375
P.E. Schoen
Affiliation:
Laboratory for Molecular Interfacial Interactions, Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375
W.T. Elam
Affiliation:
Condensed Matter and Radiation Division, Naval Research Laboratory, Washington, DC 20375
A. Ervin
Affiliation:
Chemistry Division, Naval Research Laboratory, Washington, DC 20375
S. Keller
Affiliation:
Department of Physics, University of Connecticut, Storrs, Connecticut 06269
Y.D. Zhang
Affiliation:
Department of Physics, University of Connecticut, Storrs, Connecticut 06269
J. Budnick
Affiliation:
Department of Physics, University of Connecticut, Storrs, Connecticut 06269
T. Ambrose
Affiliation:
Department of Physics, Johns Hopkins University, Baltimore, Maryland 21218
*
a)Author to whom correspondence should be addressed.
Get access

Abstract

Nanocrystalline CoxCu100−x (4 ⋚ x ⋚ 49 at. %) powders were prepared by the reduction of metal acetates in a polyol. The structure of powders was characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), extended x-ray absorption fine structure (EXAFS) spectroscopy, solid-state nuclear magnetic resonance (NMR) spectroscopy, and vibrating sample magnetometry (VSM). As-synthesized powders were composites consisting of nanoscale crystallites of face-centered cubic (fcc) Cu and metastable face-centered cubic (fcc) Co. Complementary results of XRD, HRTEM, EXAFS, NMR, and VSM confirmed that there was no metastable alloying between Co and Cu. The NMR data also revealed that there was some hexagonal-closed-packed (hcp) Co in the samples. The powders were agglomerated, and consisted of aggregates of nanoscale crystallites of Co and Cu. Upon annealing, the powders with low Co contents showed an increase in both saturation magnetization and coercivity with increasing temperature. The results suggested that during preparation the nucleation of Cu occurred first, and the Cu crystallites served as nuclei for the formation of Co.

Type
Articles
Copyright
Copyright © Materials Research Society 1995

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

REFERENCES

1See, for example, Superfine Particle Technology, edited by Ichinose, N., Ozaki, Y., and Kashu, S. (Springer-Verlag, London, 1992); Gleiter, H., Nanostructured Materials 1, 1 (1992).Google Scholar
2See papers in, for example, Molecularly Designed Ultra-fine/Nanostructured Materials, edited by Gonsalves, K. E., Chow, G. M., Xiao, T. D., and Cammarata, R.C. (Mater. Res. Soc. Symp. Proc. 351, Pittsburgh, PA, 1994); Chow, G.M., and Gonsalves, K.E., in NanoStructured Materials: Synthesis, Properties and Uses, edited by Edelstein, A. S. and Cammarata, R. C. (IOP Publishing Ltd., England, in press).Google Scholar
3Figlarz, M., Fievet, F., and Lagier, J. P., French Patent No. 82 21483 (December 21, 1982); Europe Patent No. 011 3281; US Patent No.4539041; Finland Patent No. 74416.Google Scholar
4Fievet, F., Lagier, J. P., and Figlarz, M., MRS Bull., 29 (December, 4. 1989).Google Scholar
5Fievet, F., Lagier, J. P., Blin, B., Beaudoin, B., and Figlarz, M., SolidState Ionics 32/33, 198 (1989).CrossRefGoogle Scholar
6Ducamp-Sanguesa, C., Herrera-Urbina, R., and Figlarz, M., J. SolidState Chem. 100, 272 (1992).CrossRefGoogle Scholar
7Ducamp-Sanguesa, C., Herrera-Urbina, R., and Figlarz, M., SolidState Ionics 6365, 25 (1993).Google Scholar
8Fievet, F., Fievet-Vincent, F., Lagier, J. P., Dumont, B., and Figlarz, M., J. Mater. Chem. 3, 627 (1993).CrossRefGoogle Scholar
9Childress, J. R., Chien, C. L., and Nathan, M., Appl. Phys. Lett. 56, 95 (1990).CrossRefGoogle Scholar
10Liou, S. H., Malhotra, S., Shan, Z., Sellmyer, D. J., Nans, S., Woolam, J. A., Reed, C. P., DeAngelis, R. J., and Chow, G. M., J. Appl. Phys. 70, 5882 (1991).CrossRefGoogle Scholar
11Childress, J. R. and Chien, C. L., J. Appl. Phys. 70, 5885 (1991).CrossRefGoogle Scholar
12Xiao, J. Q., Jiang, J. S., and Chien, C. L., Phys. Rev. Lett. 68, 3749 (1992).CrossRefGoogle Scholar
13Tsoukatos, A., Wan, H., Hadjipanayis, G. C., and Li, Z. G., Appl. Phys. Lett. 61, 3059 (1992).CrossRefGoogle Scholar
14Chow, G. M., Ambrose, T., Xiao, J. Q., Twigg, M. E., Baral, S., Ervin, A. M., Qadri, S. B., and Geng, C. R., Nanostructured Materials 1, 361 (1992).CrossRefGoogle Scholar
15Chow, G. M., Ambose, T., Xiao, J., Kaatz, F., and Ervin, A., Nanostructured Materials 2, 131 (1993).CrossRefGoogle Scholar
16Cobalt Monograph, edited by Centre D'Information Du Cobalt (Belgium, 1960), p. 177.Google Scholar
17Neiser, R. A., Kirkland, J. P., Elam, W. T., and Sampath, S., Nucl. Instrum. Methods, Phys. Res. Sect. A266, 220 (1988).CrossRefGoogle Scholar
18Heald, S. M., in X-ray Absorption: Principles, Applications, Techniques of EXAFS, SEXAFS, and XANES, edited by Koningsberger, D. C. and Prins, R. (John Wiley, New York, 1988), Chap. 3.Google Scholar
19Sayers, D. E. and Bunker, B. A., in X-ray Absorption: Principles, Applications, Techniques of EXAFS, SEXAFS, and XANES, edited by Koningsberger, D. C. and Prins, R. (John Wiley, New York, 1988), Chap. 6.Google Scholar
20Zhang, Y. D., Hines, W. A., Budnick, J. I., Choi, M., Sanchez, F. H., and Hasegawa, R., J. Magn. Magn. Mater. 61, 162 (1986).CrossRefGoogle Scholar
21Rehr, J. J., Mustre de Leon, J., Zabinsky, S. I., and Albers, R. C., J. Am. Chem. Soc. 113, 5135 (1991).CrossRefGoogle Scholar
22Report on the “International Workshops on Standards and Criteria in XAFS”, in X-ray Absorption Fine Structure, edited by Hasnain, S. S. (Ellis Horwood Ltd., England, 1991), p. 751.Google Scholar
23The magnitude for the Cu coordination number errors was determined by monitoring the doubling of the residual of the best fit. For further information, see Vaarkamp, M., Dring, I., Oldma, R. J., Stem, E. A., and Koningsberger, D. C., Phys. Rev. B 50, 7872 (1994).CrossRefGoogle Scholar
24Meny, C., Panissod, P., and Loloee, R., Phys. Rev. B 45, 12269 (1992).CrossRefGoogle Scholar
25Abeles, B., Appl. Solid State Science 6, 1 (1976).CrossRefGoogle Scholar
26See Ref. 16, p. 7577.Google Scholar