Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-19T03:04:15.792Z Has data issue: false hasContentIssue false

Low-temperature polymer precursor-based synthesis of nanocrystalline particles of lanthanum calcium manganese oxide (La0.67Ca0.33MnO3) with enhanced ferromagnetic transition temperature

Published online by Cambridge University Press:  01 January 2006

K. Shantha Shankar
Affiliation:
Department of Physics, Indian Institute of Science, Bangalore 560098, India
A.K. Raychaudhuri*
Affiliation:
Department of Physics, Indian Institute of Science, Bangalore 560098, India
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

We report a simple modified polymeric precursor route for the synthesis of highly crystalline and homogenous nanoparticles of lanthanum calcium manganese oxide (LCMO). The LCMO phase formation was studied by thermal analysis, x-ray powder diffraction, and infrared spectroscopy at different stages of heating. These nanocrystallites (average particle size of 30 nm) possess ferromagnetic–paramagnetic transition temperature (Tc) of 300 K, nearly 50 K higher than that of a single crystal. The Rietveld analysis of the powder x-ray diffraction data of the nanopowders reveals significant lattice contraction and reduction in unit cell anisotropy-these structural changes are correlated to the enhancement in Tc.

Type
Articles
Copyright
Copyright © Materials Research Society 2006

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

1.von Helmholt, R., Wecker, J., Holzepfel, B., Schultz, L. and Samwer, K.: Giant negative magnetoresistance in perovskitelike La2/3Ba1/3MnOx ferromagnetic films. Phys. Rev. Lett. 71, 2331 (1993).CrossRefGoogle Scholar
2.Chahara, K., Ohno, T., Kasai, M. and Kozono, Y.: Magnetoresistance in magnetic manganese oxide with intrinsic antiferromagnetic spin structure Appl. Phys. Lett. 63, 1990 (1993).CrossRefGoogle Scholar
3.Magnetoresistance Colossal Charge Ordering and Related Properties of Manganese Oxides, edited by Rao, C.N.R. and Raveau, R. (World Scientific, Singapore, 1998).CrossRefGoogle Scholar
4.Rivas, J., Hueso, L.E., Fondado, A., Rivadullo, F. and Lopez-Quintela, M.A.: Low field magnetoresistance effects in fine particles of La0.67Ca0.33MnO3 perovskites. J. Magn. Magn. Mater. 21, 57 (2000).CrossRefGoogle Scholar
5.Huang, Y.H., Xu, Z.G., Yan, C.H., Wang, Z.M., Zhu, T., Liao, C.S., Gao, S. and Xu, G.X.: Soft chemical synthesis and transport properties of La0.7Sr0.3MnO3 granular perovskites. Solid State Commun. 114, 43 (2000).CrossRefGoogle Scholar
6.Akther, A.K.M. Hossain, Cohen, L.F., Damay, F., Berenov, A., Driscoll, J.M., McN, N.Alford, ., Mathur, N.D., Blamire, M.G., and Evetts, J.E., Influence of grain size on magnetoresistance of bulk La0.67Ca0.33MnO3−d. J. Magn. Magn. Mater. 192, 263 (1999).CrossRefGoogle Scholar
7.Shankar, K. Shantha, Kar, S., Subbanna, G.N. and Raychaudhuri, A.K.: Enhanced ferromagnetic transition temperature in nanocrystalline lanthanum calcium manganese oxide (La0.67Ca0.33MnO3). Solid State Commun. 129, 479 (2003).CrossRefGoogle Scholar
8.Eeror, N.G. and Anderson, H.U. Polymeric precursor synthesis of ceramic materials, in Better Ceramics Through Chemistry II, edited by Brinker, C.J., Clark, D.E., and Ulrich, D.R. (Mater. Res. Soc. Symp. Proc. 173, Pittsburgh, PA, 1986), pp. 571577.Google Scholar
9.Li, X., Zhang, H., Chi, F., Li, S., Xu, B. and Zhao, M.: Synthesis of nanocrystalline composite oxides La1−xSrxFe1−yCoyO3 with the perovskite structure using polyethylene glycol-gel method. Mater. Sci. Eng. B 18, 209 (1993).Google Scholar
10.Paris, E.C., Leite, E.R., Longo, E. and Varela, J.A.: Synthesis of PbTiO3 by use of polymeric precursors. Mater. Lett. 37, 1 (1998).CrossRefGoogle Scholar
11.De Keijser, Th.H., Langford, J.I., Mittemeijer, E.J. and Vogels, A.B.P.: Use of the Voigt function in a single-line method for the analysis of x-ray diffraction line broadening. J. Appl. Crystallogr. 15, 308 (1982).CrossRefGoogle Scholar
12.Apai, G., Hamilton, J.F., Stohr, J. and Thompson, A.: Extended x-ray absorption fine structure of small Cu and Ni clusters: Binding-energy and bond-length changes with cluster size. Phys. Rev. Lett. 43, 165 (1979).Google Scholar
13.Martinera, H.T. and Burfoot, J.C.: Grain size effects on properties of some ferroelectric ceramics. J. Phys. C: Solid State Phys. 7, 3182 (1974).Google Scholar
14.Chattopadhyay, S., Ayyub, P., Palkar, V.R., Gurjar, A.V., Wankar, R.M. and Multani, M.: Finite-size effects in antiferroelectric PbZrO3 nanoparticles. J. Phys.: Condens. Matter 9, 8135 (1997).Google Scholar
15.Noto, V.D., Longo, D. and Munchow, V.: Ion-oligomer interactions in poly(ethylene glycol)400/(LiCl)x electrolyte complexes. J. Phys. Chem. B 103, 2636 (1999).CrossRefGoogle Scholar
16.Vazquez-Vazquez, C., Blanco, M.C., Lopez, M. Arturo, Sanchez, R.D., Rivas, J. and Oseroff, S.B.: Characterization of La0.67Ca0.33MnO3 particles prepared by the sol-gel route. J. Mater. Chem. 8, 991 (1998).Google Scholar
17.Yi, T., Gao, S., Qi, X., Zhu, Y., Cheng, F., Huang, Y., Liao, C. and Yan, C.: Low-temperature synthesis and magnetism of La0.75Ca0.25MnO3 nanoparticles. J. Phys. Chem. Solids 61, 1407 (2000).Google Scholar
18.Shim, I.B, Bae, S.Y., Oh, Y.J. and Choi, S.Y.: Magnetic homogeneity in colossal magnetoresistive La0.67Ca0.33MnO3-d perovskite ceramics. Solid State Ionics 108, 241 (1998).Google Scholar
19.Weissmuller, J. and Cahn, J.W.: Mean stresses in microstructures due to interface stresses: A generalization of a capillary equation for solids. Acta Mater. 45, 1899 (1997).Google Scholar
20.Congeduti, A., Postorino, P., Caramagno, E., Nardone, M., Kumar, A. and Sarma, D.D.: Anomalous high pressure dependence of the Jahn–Teller phonon in La0.75Ca0.25MnO3. Phys. Rev. Lett. 86, 1251 (2001).Google Scholar