[ ] [Image] [ ] Volume: Page/Article: ------------------------------------------------------------------------ Article Collection: View Collection Help (Click on the [Check Box] to add an article.) ------------------------------------------------------------------------ Phys. Rev. B 34, 1784–1791 (1986) [Issue 3 – 1 August 1986 ] [ Previous article | Next article | Issue 3 contents ] [Add to article collection] View Page Images or PDF (1729 kB) ------------------------------------------------------------------------ Ferromagnetic phases of bcc and fcc Fe, Co, and Ni V. L. Moruzzi and P. M. Marcus IBM Thomas J. Watson Research Center, P. O. Box 218, Yorktown Heights, New York 10598 K. Schwarz and P. Mohn Institute of Technical Electrochemistry, Technical University of Vienna, A-1060 Vienna, Austria Received 5 March 1986 The different magnetic phases of the bcc and fcc forms of Fe, Co, and Ni are studied by analyzing total-energy surfaces in moment-volume parameter space obtained from energy-band calculations using a local-spin-density approximation. The surfaces, found by calculating total energies while holding both the magnetic moment and the volume fixed, offer a method for studying phases that are inaccessible to traditional self-consistent-field methods. We find that magnetic moments can change discontinuously with volume and that there are ranges of coexistence for different magnetic phases. In the multiphase ranges, these elemental magnetic systems exhibit metamagnetic behavior. Our results show that bcc Co is ferromagnetic for all volumes studied, that fcc Co can exist in either a nonmagnetic or a ferromagnetic phase, and that there is a range of volumes where the two phases can coexist. For Fe, the bcc form exhibits a stable ferromagnetic phase for all volumes considered, but the fcc form can exist in any of three phases—a nonmagnetic, a low-spin, and a high-spin phase—all of which can coexist in limited volume ranges. For Ni, the fcc form exhibits a stable ferromagnetic phase, but the bcc form can exist in both a nonmagnetic and, at expanded volumes, a ferromagnetic phase. The volume ranges for all magnetic phases are clearly identified for the bcc and fcc forms of Fe, Co, and Ni. ©1986 The American Physical Society URL: http://link.aps.org/abstract/PRB/v34/p1784 DOI: 10.1103/PhysRevB.34.1784 PACS: 71.25.Pi, 75.10.Lp, 75.30.Kz, 75.50.Bb ------------------------------------------------------------------------ [Add to article collection] View Page Images or PDF (1729 kB) [ Previous article | Next article | Issue 3 contents ] ------------------------------------------------------------------------ References (Reference links marked with [dot] may require a separate subscription.) 1. W. Kohn and L. Sham, Phys. Rev. 140, A1133 (1965). 2. V. L. Moruzzi, J. F. Janak, and A. R. Williams, Calculated Electronic Properties of Metals (Pergamon, New York, 1978). 3. O. K. Andersen, J. Madsen, U. K. Poulsen, O. Jepsen and J. Kollar, Physica 86&88B, 249 (1977). 4. D. M. Roy and D. G. Pettifor, J. Phys. F 7, L183 (1977) [[dot] INSPEC]. 5. A. R. Williams, V. L. Moruzzi, J. Kübler and K. Schwarz, Bull. Am. Phys. Soc. 29, 278 (1984); K. Schwarz and P. Mohn, J. Phys. F 14, L129 (1984). In this work we only consider ferromagnetic order. The fixed spin-moment method has not yet been extended to the more complicated problem of antiferromagnetic order. 6. P. H. Dederichs, S. Blügel, R. Zeller and H. Akai, Phys. Lett. 53, 2512 (1984). 7. A. R. Williams, J. Kübler and C. D. Gelatt, Jr.,, Phys. Rev. B 19, 6094 (1979). 8. U. von Barth and L. Hedin, J. Phys. C 5, 1629 (1972) [[dot] INSPEC]. 9. J. F. Janak, Solid State Commun. 25, 53 (1978) [[dot] INSPEC]. 10. V. L. Moruzzi, Thesis, Technical University of Vienna, Vienna, Austria, 1985. See also, P. M. Marcus and V. L. Moruzzi, Solid State Commun. 55, 971 (1985) [[dot] INSPEC]. 11. V. L. Moruzzi, P. M. Marcus, K. Schwarz and P. Mohn, J. Magn. Magn. Mater. 54-57, 955 (1986). 12. P. M. Marcus, V. L. Moruzzi, and K. Schwarz, in Computer-based Microscopic Description of the Structure and Properties of Materials, Vol. 63 of Materials Research Society Symposia Proceedings, edited by J. Broughton, W. Krakow, and S. T. Pantelides (Materials Research Society, Pittsburg, 1986). 13. G. A. Prinz, Phys. Rev. Lett. 54, 1051 (1985). 14. J. Kübler, Phys. Lett. 81A, 81 (1981). 15. E. P. Wohlfarth and P. Rhodes, Philos. Mag. 7, 1817 (1962); M. Shimizu, J. Phys. (Paris) 43, 155 (1982) [[dot] INSPEC]. 16. The model of magnetic behavior used here only includes spin magnetization, which requires the moment to be parallel or antiparallel to the applied magnetic field. Negative fields, i.e., fields opposite to the direction of the moment, can be tolerated in the ferromagnetic state because the model provides an energy barrier to reversing the magnetization direction. When a threshold negative field is exceeded, the system will abruptly assume the opposite magnetization. Mechanisms outside the model, e.g., rotation of the spin direction, may permit spin reversal at smaller threshold fields. 17. At the crossing point of the fcc and bcc curves in Fig. 9, which is where a transition to the fcc state would take place if the transition occurred at constant volume, the pressure in the bcc state is 140 kbar. The (extrapolated) experimental phase diagram for Fe indicates a transition at T=0 from bcc to hcp (alpha to epsilon) at about 140 kbar; [see Lin-gun Liu and L. H. Bassett, J. Geophys. Res. 80, 3777 (1975)] [[dot] SPIN][[dot] INSPEC]. 18. C. S. Wang, B. M. Klein and H. Krakauer, Phys. Rev. Lett. 54, 1852 (1985). 19. J. Kübler, in the Proceedings of the Institute von Laue-Langevin Workshop on 3d Metallic Magnetism, Grenoble, France, 1983, edited by D. Givord and K. Ziebeck (unpublished). 20. D. Bagayoko and J. Callaway, Phys. Rev. B 28, 5419 (1983). 21. K. B. Hathaway, H. F. J. Jansen and A. J. Freeman, Phys. Rev. B 31, 7603 (1985). 22. S. H. Vosko, L. Wilk and M. Nusair, Can. J. Phys. 58, 1200 (1980) [ [dot] INSPEC]; S. H. Vosko and L. Wilk, Phys. Rev. B 22, 3812 (1980). ------------------------------------------------------------------------ [Add to article collection] View Page Images or PDF (1729 kB) [Show Articles Citing This One] Requires Subscription [ Previous article | Next article | Issue 3 contents ] ------------------------------------------------------------------------ [ APS | APS Journals | PROLA Homepage | Browse | Search ]