Abstract
Half-metallic materials are characterized by the coexistence of metallic behaviour for one electron spin and insulating behaviour for the other. Thus, the electronic density of states is completely spin polarized at the Fermi level, and the conductivity is dominated by these metallic single-spin charge carriers. This exotic physical property could have a significant effect on technological applications related to magnetism and spin electronics. Some ferromagnetic systems, such as Heusler compounds1 and chromium dioxide2, have been predicted theoretically to be half-metallic. However, a half-metallic system has not been demonstrated directly and the predictions are still in doubt3,4. Here we report spin-resolved photoemission measurements of a ferromagnetic manganese perovskite, La0.7Sr0.3MnO3, which directly manifest the half-metallic nature well below the Curie temperature. For the majority spin, the photoemission spectrum clearly shows a metallic Fermi cut-off, whereas for the minority spin, it shows an insulating gap with disappearance of spectral weight at ∼0.6 eV binding energy.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
Purchase on Springer Link
Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
de Groot, R. A., Muller, F. M., van Engen, P. G. & Buschow, K. H. J. New class of materials: half-metallic ferromagnets. Phys. Rev. Lett. 50, 2024–2027 (1983).
Schwarz, K. CrO2 predicted as a half-metallic ferromagnet. J. Phys. F 16, L211–L215 (1986).
Bona, G. L., Meier, F., Taborelli, M., Bucher, E. & Schmidt, P. H. Spin polarized photoemission from NiMnSb. Solid State Commun. 56, 391–394 (1985).
Kämper, K. P., Schmitt, W., Güntherodt, G., Gambin, R. J. & Ruf, R. CrO2 — a new half-metallic ferromagnet? Phys. Rev. Lett. 59, 2788–2791 (1988).
Hanssen, K. E. H. M., Mijnarends, P. E., Rabou, L. P. L. M. & Buschow, K. H. J. Positron-annihilation study of the half-metallic ferromagnet NiMnSb: experiment. Phys. Rev. B 42, 1533–1540 (1990).
Jonker, G. H. & van Santen, J. H. Ferromagnetic compounds of manganese with perovskite structure. Physica 16, 337–349 (1950).
Tokura, Y. et al. Giant mangetotransport phenomena in filling-controlled Kondo lattice system: La1−xSrxMnO3. J. Phys. Soc. Jpn 63, 3931–3935 (1994).
von Helmholt, R., Wecker, J., Holszapfel, B., Schultz, L. & Samwer, K. Giant negative magnetoresistance in perovskitelike La2/3Ba1/3MnOx ferromagnetic films. Phys. Rev. Lett. 71, 2331–2334 (1993).
Jin, S. et al. Thousandfold change in resistivity in magnetoresistive La-Ca-Mn-O films. Science 264, 413–415 (1994).
Zener, C. Interaction between the d-shells in the transition metals. II. Ferromagnetic compounds of manganese with perovskite structure. Phys. Rev. 82, 403–405 (1951).
Millis, A. J., Shraiman, B. I. & Mueller, R. Dynamic Jahn–Teller effect and colossal magnetoresistance in La1−xSrxMnO3. Phys. Rev. Lett. 77, 175–178 (1996).
Park, J.-H. et al. Electronic aspects of the ferromagnetic transition in manganese perovskites. Phys. Rev. Lett. 76, 4215–4218 (1996).
de Teresa, J. M. et al. Evidence for magnetic polarons in the magnetoresistive perovskites. Nature 386, 256–258 (1997).
Okimoto, Y. et al. Anomalous variation of optical spectra with spin polarization in double exchange ferromagnet: La1−xSrxMnO3. Phys. Rev. Lett. 75, 109–112 (1995).
Hwang, H. Y., Cheong, S.-W., Ong, N. P. & Batlogg, B. Spin-polarized intergrain tunneling in La2/3Sr1/3MnO3. Phys. Rev. Lett. 77, 2041–2044 (1996).
de Boer, P. K., van Leuken, H., de Groot, R. A., Rojo, T. & Barberis, G. E. Electronic structure of La0.5Ca0.5MnO3. Solid State Commun. 102, 621–626 (1997).
Pickett, W. E. & Singh, D. J. Electronic structure and half-metallic transport in the La1−xCaxMnO3system. Phys. Rev. B 53, 1146–1160 (1996).
Lu, Y. et al. Large magnetotunneling effect at low magnetic fields in micrometer-scale epitaxial La0.67Sr0.33MnO3tunnel junctions. Phys. Rev. B 54, R8357–R8360 (1996).
Sun, J. Z., Krusin-Elbaum, L., Duncombe, P. R., Gupta, A. & Laibowwitz, R. B. Spin-polarized tunneling in doped perovskite manganate trilayer junctions. Appl. Phys. Lett. 70, 1769–1771 (1997).
Kwon, C. et al. Stress-induced effects in epitaxial (La0.7Sr0.3)MnO3films. J. Magn. Magn. Mater. 172, 229–236 (1997).
Vescovo, E. et al. The U5UA SGM-beamline: First Tests on the Performances A-25 (Activity Rep. 1996, National Synchrotron Light Source, Brookhaven National Lab, Upton, 1997).
Sarma, D. D. et al. Temperature-dependent photoemission spectral weight in La0.6Sr0.4MnO3. Phys. Rev. B 53, 6873–6877 (1996).
Saitoh, T. et al. La1−xSrxMnO3studied by photoemission and X-ray absorption spectroscopy. Phys. Rev. B 51, 13942–13951 (1995).
Trajanovic, Z. et al. Growth of colossal magnetoresistance thin films on silicon. Appl. Phys. Lett. 69, 1005–1007 (1996).
Acknowledgements
We thank J. Hastings for discussions. NSLS is supported by the US Department of Energy; the work in the University of Maryland was partially supported by the US Office of Naval Research.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Park, JH., Vescovo, E., Kim, HJ. et al. Direct evidence for a half-metallic ferromagnet. Nature 392, 794–796 (1998). https://doi.org/10.1038/33883
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/33883
This article is cited by
-
Insight into the structural, electronic, mechanical, magnetic and thermodynamic properties of the new half-metallic ferromagnetic full-Heusler alloys Cr2YZ (Z = Si, Ge, Sn) from initio calculations
Indian Journal of Physics (2024)
-
Probing the structural, mechanical, phonon, thermal, and transport properties of magnetic halide perovskites XTiBr3 (X = Rb, Cs) through ab-initio results
Scientific Reports (2023)
-
Thickness-dependent ferromagnetic, ferroelectric, and energy storage performances of (Bi0.5Na0.5)0.94Ba0.06TiO3/La0.67Sr0.33MnO3 composite films by pulsed laser deposition
Journal of Materials Science: Materials in Electronics (2023)
-
Nanoscale Etching of La0.7Sr0.3MnO3 Without Etch Lag Using Chlorine Based Inductively Coupled Plasma
Electronic Materials Letters (2023)
-
Electrically manipulating magnetization reversal via energy band engineering
Science China Physics, Mechanics & Astronomy (2023)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.