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Highly dense and compositionally inhomogeneous nano-agglomerates in an epitaxial La0.8Sr0.2MnO3 thin film grown on (100)SrTiO3

Published online by Cambridge University Press:  01 March 2005

Y.L. Zhu
Affiliation:
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China
X.L. Ma*
Affiliation:
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China
D.X. Li
Affiliation:
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China
H.B. Lu
Affiliation:
Laboratory of Optical Physics, Institute of Physics & Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, People's Republic of China
Z.H. Chen
Affiliation:
Laboratory of Optical Physics, Institute of Physics & Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, People's Republic of China
G.Z. Yang
Affiliation:
Laboratory of Optical Physics, Institute of Physics & Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, People's Republic of China
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

Microstructures in the thin film of La0.8Sr0.2MnO3 grown on (100) SrTiO3 by laser molecular beam epitaxy were characterized by transmission electron microscopy. Highly dense and dimensionally uniform nano-agglomerates were found embedded in thin film of La0.8Sr0.2MnO3. High-angle angular dark-field imaging, elemental mapping, and compositional analysis revealed that the nano-agglomerates are rich in manganese and poor in lanthanum. The ratio of Mn/La in the nano-agglomerates fluctuates. A salient feature of this compositional fluctuation within the nanoscale isthe formation of cubic MnO phase, which appears as the core of the nano-agglomerates.The La0.8Sr0.2MnO3 film is domain-oriented and two domains were identified on the basis of orthorhombic lattice. The orientation relationships between La0.8Sr0.2MnO3 domains and MnO were determined as [010]LSMO,1//[001]MnO and (100)LSMO,1//(110)MnO; [101]LSMO,2//[001]MnO and (010)LSMO,2//(100)MnO. The domain structuresand compositional inhomogeneities within nanoscale result in a textured microstructure, which is one of the most important parameters for tuning electronic properties in colossal magnetoresistance oxides.

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Articles
Copyright
Copyright © Materials Research Society 2005

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References

REFERENCES

1.Kusters, R.M., Singleton, J., Keen, D.A., Mcgreevy, R.M. and Hayes, W.: Magnetoresistance measurements on the magnetic semiconductor Nd0.5Pb0.5MnO3. Physica B 155, 362 (1989).CrossRefGoogle Scholar
2.Von Helmolt, R., Wecker, J., Holzapfel, B., Schultz, L. and Samwer, K.: Giant negative magnetoresistance in perovskitelike La2/3Ba1/3MnOx ferromagnetic films. Phys. Rev. Lett. 71, 2331 (1993).CrossRefGoogle Scholar
3.Chahara, K., Ohno, T., Kasai, M. and Kozono, Y.: Magnetoresistance in magnetic manganese oxide with intrinsic antiferromagnetic spin structure. Appl. Phys. Lett. 63, 1190 (1993).CrossRefGoogle Scholar
4.Jin, S., Tiefel, T.H., McCormack, M., Fastnacht, P.A., Ramesh, R. and Chen, L.H.: Thousandfold change in resistivity in magnetoresistive La-Ca-MnO films. Science 264, 413 (1994).CrossRefGoogle Scholar
5.Thomas, K.A., de Silva, P.S.I.P.N., Cohen, L.F., Hossain, A., Rajeswari, M., Venkatesan, T., Hishes, R. and MacManus-Driscoll, J.L.: Influence of strain and microstructure on magnetotransport in La0.7Ca0.3MnO3 thin films. J. Appl. Phys. 84, 3939 (1998).CrossRefGoogle Scholar
6.Suzuki, Y., Hwang, H.Y., Cheong, S-W. and van Dover, R.B.: The role of strain in magnetic anisotropy of manganite thin films. Appl. Phys. Lett. 71, 140 (1997).CrossRefGoogle Scholar
7.Mitchell, J.F., Argyriou, D.N., Potter, C.D., Hinks, D.G., Jorgensen, J.D. and Bader, S.D.: Structural phase diagram of La1−xSrxMnO3+δ: Relationship to magnetic and transport properties. Phys. Rev. B 54, 6172 (1996).CrossRefGoogle ScholarPubMed
8.Lebedev, O.I., Van Tendeloo, G., Amelinckx, S., Razavi, F. and Habermeier, H.U.: A Periodic microtwinning as a possible mechanism for the accommodation of the epitaxial film-substrate mismatch in the La1−xSrxMnO3/SrTiO3 system. Philos. Mag. A 81, 797 (2001).CrossRefGoogle Scholar
9.Zandbergen, H.W., Jansen, J., Freisem, S., Nojima, T. and Aarts, J.: Atomic structure and microstructure of very thin films of La0.73Ca0.27MnO3 on SrTiO3. Philos. Mag. A 80, 337 (2000).CrossRefGoogle Scholar
10.Ma, X.L., Zhu, Y.L., Meng, X.M., Lu, H.B., Chen, F., Chen, Z.H., Yang, G.Z. and Zhang, Z.: Oriented domains in a thin film of La0.8Sr0.2MnO3 prepared by laser molecular-beam epitaxy. Philos. Mag. A 82, 1331 (2002).Google Scholar
11.Zhu, Y.L., Ma, X.L., Li, D.X., Lu, H.B., Chen, Z.H. and Yang, G.Z.: Structure and microstructural characteristics in the thin films of La1-xSrxMnO3 (x = 0.1, 0.2, 0.3). Mater. Lett. 58, 1485 (2004).CrossRefGoogle Scholar
12.Zhang, M., Ma, X.L., Li, D.X., Lu, H.B., Chen, Z.H. and Yang, G.Z.: Microdomains in rhombohedral La0.7Sr0.3MnO3 thin films. Phys. Status Solidi A 196, 365 (2003).CrossRefGoogle Scholar
13.Nath, T.K., Rao, R.A., Lavric, D., Eom, C.B., Wu, L. and Tsui, F.: Effect of three-dimensional strain states on magnetic anisotropy of La0.8Ca0.2MnO3 epitaxial thin films. Appl. Phys. Lett. 74, 1615 (1999).CrossRefGoogle Scholar
14.Salamon, M.B. and Jaime, M.: The physics of manganites: Structure and transport. Rev. Mod. Phys. 73, 583 (2001).CrossRefGoogle Scholar
15.Zhang, L., Israel, C., Biswas, A., Greene, R.L. and de Lozanne, A.: Direct observation of percolation in a manganite thin film. Science 298, 805 (2002).CrossRefGoogle Scholar
16.Mathur, N. and Littlewood, P.: Mesoscopic texture in manganites. Phys. Today 56, 25 (2003).CrossRefGoogle Scholar
17.Kim, K.H., Uehara, M. and Cheong, S.W.: High-temperature charge-ordering fluctuation in manganites. Phys. Rev. B 62, R11945 (2000).CrossRefGoogle Scholar
18.Ahn, K.H., Lookman, T. and Bishop, A.R.: Strain-induced metal– insulator phase coexistence in perovskite manganites. Nature 428, 401 (2004).CrossRefGoogle ScholarPubMed
19.Fäth, M., Freisem, S., Menovsky, A.A., Tomioka, Y., Aarts, J. and Mydosh, J.A.: Spatially inhomogeneous metal-insulator transition in doped manganites. Science 285, 1540 (1999).CrossRefGoogle ScholarPubMed
20.Renner, Ch., Aeppli, G., Kim, B.G., Soh, Y.A. and Cheong, S.W.: Atomic-scale images of charge ordering in a mixed-valence manganite. Nature 416, 518 (2002).CrossRefGoogle Scholar
21.Uehara, M., Mori, S., Chen, C.H. and Cheong, S.W.: Percolative phase separation underlies colossal magnetoresistance in mixed-valent manganites. Nature 399, 560 (1999).CrossRefGoogle Scholar
22. JCPDS-ICDD, the International Center for Diffraction Data, Newtown Square, PA 1995.Google Scholar
23.Hirsch, P.B., Howie, A., Nicholson, R.B., Pashley, D.W. and Whelan, M.J.: Electron Microscopy of Thin Crystals. (Butterworths, London, U.K., 1965) p. 341.Google Scholar
24.Kuo, K.H., Ye, H.Q. and Wu, Y.K.: The Applications of Electron-Diffraction Patterns in Crystallography (Scientific Press, Beijing, China, 1980), Chap. 5, p. 217 (in Chinese).Google Scholar
25.Tu, K-N., Mayer, J.W., and Feldmen, L.C.: Electronic Thin Film Sciences: For Electrical Engineers & Material Scientists (Macmillan College Publishing Company, 1992), Chap. 5, pp. 119, 126. Scientific Press, Beijing, China, 1997, translated into Chinese.Google Scholar
26.Chen, G.J., Chang, Y.H. and Hsu, H.W.: The effect of microstructure and secondary phase on magnetic and electrical properties of La-deficient La≤ ≤ 0.3) films. J. Magn. Magn. Mater. 219, 317 (2000).CrossRefGoogle Scholar
27.Han, K. and Yu-Zhang, K.: Transmission-electron-microscopy study of epitaxial lanthanum-manganite thin films on SrTiO3. Philos. Mag. B 79, 897 (1999).CrossRefGoogle Scholar
28.Yu, Q., Gorbenko, I.E., Graboy, A.R., Kaul, H. and Zandbergen, W.: HREM and XRD characterization of epitaxial perovskite manganites. J. Magn. Magn. Mater. 211, 97 (2000).Google Scholar
29.He, J.Q., Jia, C.J., Schubert, J. and Wang, R.H.: Microstructures of epitaxial La0.7Ca0.3MnO3 thin films grown on SrTiO3 and NdGaO3 substrates. J. Cryst. Growth 265, 241 (2004).CrossRefGoogle Scholar
30.Lu, C.J., Wang, Z.L., Kwon, C. and Jia, Q.X.: Microstructure of epitaxial La0.7Ca0.3MnO3 thin films grown on LaAlO3 and SrTiO3. J. Appl. Phys. 88, 4032 (2000).CrossRefGoogle Scholar
31.Millis, A.J.: Lattice effects in magnetoresistive manganese perovskites. Nature 392, 147 (1998).CrossRefGoogle Scholar