Hostname: page-component-76fb5796d-wq484 Total loading time: 0 Render date: 2024-04-27T04:10:05.143Z Has data issue: false hasContentIssue false

Intrinsic Properties of Doped Lanthanum Manganite

Published online by Cambridge University Press:  15 February 2011

G. Jeffrey Snyder
Affiliation:
Department of Applied Physics, Stanford University, Stanford, California 94305-4090
Ron Hiskes
Affiliation:
Hewlett-Packard, Palo Alto, California 94303-0867
Steve DiCarolis
Affiliation:
Hewlett-Packard, Palo Alto, California 94303-0867
M. R. Beasley
Affiliation:
Department of Applied Physics, Stanford University, Stanford, California 94305-4090
T. H. Geballe
Affiliation:
Department of Applied Physics, Stanford University, Stanford, California 94305-4090
Get access

Abstract

An investigation designed to display the intrinsic properties of perovskite manganites was accomplished by comparing the behavior of bulk samples with that of thin films; the results show the "colossal magneto resistance" at very low temperatures is not an intrinsic property of the thermodynamically stable 1/3 doped material. Epitaxial 1500 Å films of perovskite La0.67Ca0.33MnO3 and La0.67Sr0.33MnO3 were grown by solid source chemical vapor deposition on LaA1O3 and post annealed in oxygen at 950°C. Crystals were prepared by LASER heated pedestal growth. The magnetic and electrical transport properties are essentially the same. Below Tc/2 the intrinsic magnetization decreases as T2 (as can be expected for itinerant electron ferromagnets) while the intrinsic resistivity increases proportional to T2. The constant and T2 coefficients of the resistivity are largely independent of magnetic field and alkaline earth element (Ca, Sr or Ba). We identify three distinct types of negative magnetoresistance. The largest effect is observed near the Curie temperature and is likely to be due to magnetic critical scattering. There is also magnetoresistance associated with the net magnetization of polycrystalline samples. The high temperature (above Tc) resistivity of La0.67Ca0.33MnO3 is consistent with small polaron hopping conductivity with a transition at 750K, while La0.67Sr0.33MnO3 does not exhibit activated conductivity until about 500K, well above Tc. The limiting low and high temperature resistivities may place a limit on the maximum possible magnetoresistance of these materials.

Type
Research Article
Copyright
Copyright © Materials Research Society 1996

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

1. Goodenough, J. B. and Longo, J. M., in Landolt-Bdrnstein Tabellen (Springer, Berlin, 1970), Vol. III/4a.Google Scholar
2. vanRoosmalen, J. A. M. and Cordfunke, E. H. P., J. Solid State Chem. 110, 106 (1994).Google Scholar
3. Jin, S., Tiefel, T. H., McCormack, M., Fastnacht, R. A., Ramesh, R., and Chen, L. H., Science 264, 413 (1994).Google Scholar
4. Hiskes, R., DiCarolis, S. A., Fouquet, J. et al. , Mat. Res. Soc. Symp. Proc. 335, 299 (1994).Google Scholar
5. Ju, H. L., Gopalakrishnan, J., Peng, J. L., Li, G. C. X. Qi, Venkatesan, T., and Greene, R. L., Phys. Rev. B 51, 6143 (1995).Google Scholar
6. Schiffer, P., Ramirez, A. P., Bao, W., and Cheong, S.-W., Phys. Rev. Lett. (1995).Google Scholar
7. Kubo, K. and Ohata, N., J. Phys. Soc. Jpn. 33, 21 (1972).Google Scholar
8. Ju, H. L., Kwon, C., Li, Q., Greene, R. L., and Venkatesan, T., Appl. Phys. Lett. 65, 2108 (1994).Google Scholar
9. Mott, N., Electronic Processes in non-Crystalline Materials (Clarendon Press, Oxford, 1971).Google Scholar
10. vonMolnár, S. and Methfessel, S., J. Appl. Phys. 38, 959 (1967).Google Scholar
11. Lonzarich, G. G. and Taillefer, L., J. Phys. C: Solid State Phys. 18, 4339 (1985).Google Scholar
12. Campell, I. A. and Fert, A., in Ferromagnetic Materials, edited by Wholfarth, E. P. (North Holland, New York, 1982), Vol.3, Chap. 9.Google Scholar
13. Millis, A. J., Littlewood, P. B., and Shraiman, B. I., Phys. Rev. Lett. 74, 5144 (1995).Google Scholar
14. Hundley, M. F., Neumeier, J. J., Heffner, R. H., Jia, Q. X., Wu, X. D., and Thompson, J. D., J. Appl. Phys. (to be published).Google Scholar