Charge-doping and chemical composition-driven magnetocrystalline anisotropy in CoPt core-shell alloy clusters

  • P. Ruiz-DíazEmail author
  • M. Muñoz-Navia
  • J. Dorantes-Dávila
Research Paper


Charge-doping together with 3d-4d alloying emerges as promising mechanisms for tailoring the magnetic properties of low-dimensional systems. Here, throughout ab initio calculations, we present a systematic overview regarding the impact of both electron(hole) charge-doping and chemical composition on the magnetocrystalline anisotropy (MA) of CoPt core-shell alloy clusters. By taking medium-sized Co n Pt m (N = n + m = 85) octahedral-like alloy nanoparticles for some illustrative core-sizes as examples, we found enhanced MA energies and large induced spin(orbital) moments in Pt-rich clusters. Moreover, depending on the Pt-core-size, both in-plane and off-plane directions of magnetization are observed. In general, the MA of these binary compounds further stabilizes upon charge-doping. In addition, in the clusters with small MA, the doping promotes magnetization switching. Insights into the microscopical origins of the MA behavior are associated to changes in the electronic structure of the clusters.

Graphical abstract

The magnetic properties of atomic-scale systems cannot be elucidated from their bulk counterparts. In particular, the magneto-crystallyne anisotropy energy (MAE), which arises mainly from the spin-orbit interactions is very sensitive to countless factors. The intricate behaviour comes from the interplay bounded by the strong chemical composition-dependence and the local environment. Here, we show that alloying together with charge-doping offers an appealing route for further tailoring the magnetic properties of cluster-alloys.


Charge-doping CoPt core-shell alloy clusters Ab initio calculations Magnetic anisotropy Binary nanoalloys Modeling and simulation 



P.R.D and M .M.N thankfully acknowledge the computer resources, technical expertise, and support provided by the Laboratorio Nacional de Supercómputo del Sureste de México (LNS). The authors also thank J. Rentería-Arriaga and J.C. Sánchez-Leaños for technical support.

Funding information

J.D.D acknowledges the financial support to CONACyT trough grant 256132 and M.M.N to PROALMEX 245115.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.


  1. Barcaro G, Ferrando R, Fortunelli A, Rossi G (2010) Exotic supported copt nanostructures: from clusters to wires. J Phys Chem Lett 1(1):111–115. CrossRefGoogle Scholar
  2. Bergman A, Hellsvik J, Bessarab P F, Delin A (2016) Spin relaxation signature of colossal magnetic anisotropy in platinum atomic chains. Sci Rep 6:36,872. CrossRefGoogle Scholar
  3. Blöchl P E (1994) Projector augmented-wave method. Phys Rev B 50:17,953–17,979. CrossRefGoogle Scholar
  4. Bruno P (1989) Tight-binding approach to the orbital magnetic moment and magnetocrystalline anisotropy of transition-metal monolayers. Phys Rev B 39:865–868. CrossRefGoogle Scholar
  5. Cui P, Choi J H, Lan H, Cho J H, Niu Q, Yang J, Zhang Z (2016) Quantum stability and magic lengths of metal atom wires. Phys Rev B 93:224,102. CrossRefGoogle Scholar
  6. Dasa T R, Ignatiev P A, Stepanyuk V S (2012) Effect of the electric field on magnetic properties of linear chains on a Pt(111) surface. Phys Rev B 85:205,447. CrossRefGoogle Scholar
  7. Dasa T R, Ruiz-Díaz P, Brovko OO, Stepanyuk VS (2013) Tailoring magnetic properties of metallic thin films with quantum well states and external electric fields. Phys Rev B 88:104,409. CrossRefGoogle Scholar
  8. Díaz-Sánchez LE, Dorantes-Dávila J, Pastor G M (2013) Local and chemical environment dependence of the magnetic properties of corh core-shell nanoparticles. Phys Rev B 88:134,423. CrossRefGoogle Scholar
  9. Donati F, Gragnaniello L, Cavallin A, Natterer F D, Dubout Q, Pivetta M, Patthey F, Dreiser J, Piamonteze C, Rusponi S, Brune H (2014) Tailoring the magnetism of co atoms on graphene through substrate hybridization. Phys Rev Lett 113:177,201. CrossRefGoogle Scholar
  10. Donati F, Rusponi S, Stepanow S, Wäckerlin C, Singha A, Persichetti L, Baltic R, Diller K, Patthey F, Fernandes E, Dreiser J, Šljivančanin ž, Kummer K, Nistor C, Gambardella P, Brune H (2016) Magnetic remanence in single atoms. Science 352(6283):318–321. CrossRefGoogle Scholar
  11. Dreizler R M, Gross E K U (1990) Density functional theory. Springer, Berlin, pp 186–187CrossRefGoogle Scholar
  12. Gerstmann U, Deák P, Rurali R, Aradi B, Frauenheim T, Overhof H (2003) Charge corrections for supercell calculations of defects in semiconductors. Phys B Condens Matter 340–342:190–194. Proceedings of the 22nd International Conference on Defects in Semiconductors. CrossRefGoogle Scholar
  13. Gleiter H, Weissmüller J, Wollersheim O, Würschum R (2001) Nanocrystalline materials: a way to solids with tunable electronic structures and properties. Acta Mater 49(4):737–745CrossRefGoogle Scholar
  14. Gruner M E (2010) Core-shell morphologies of fept and copt nanoparticles: an ab initio comparison. J Phys Conf Ser 200(7):072,039. CrossRefGoogle Scholar
  15. Gruner M E, Rollmann G, Entel P, Farle M (2008) Multiply twinned morphologies of fept and copt nanoparticles. Phys Rev Lett 100:087,203CrossRefGoogle Scholar
  16. Hohenberg P, Kohn W (1964) Inhomogeneous electron gas. Phys Rev 136:B864–B871. CrossRefGoogle Scholar
  17. Hsu P J, Kubetzka A, Finco A, Romming N, von Bergmann K, Wiesendanger R (2017) Electric-field-driven switching of individual magnetic skyrmions. Nat Nano 12(2):123–126. CrossRefGoogle Scholar
  18. Jungwirth T, Marti X, Wadley P, Wunderlich J (2016) Antiferromagnetic spintronics. Nat Nanotechnol 11:231–241CrossRefGoogle Scholar
  19. Khajetoorians AA, Wiebe J, Chilian B, Wiesendanger R (2011) Realizing all-spin-based logic operations atom by atom. Science 332(6033):1062–1064. CrossRefGoogle Scholar
  20. Khajetoorians A A, Wiebe J, Chilian B, Lounis S, Blügel S, Wiesendanger R (2012) Atom-by-atom engineering and magnetometry of tailored nanomagnets. Nat Phys 8(6):497–503CrossRefGoogle Scholar
  21. Kohn W, Sham L J (1965) Self-consistent equations including exchange and correlation effects. Phys Rev 140:A1133–A1138. CrossRefGoogle Scholar
  22. Kresse G, Furthmüller J (1996) Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys Rev B 54:11,169–11,186. CrossRefGoogle Scholar
  23. Kresse G, Hafner J (1993) Ab initio molecular dynamics for liquid metals. Phys Rev B 47:558–561. CrossRefGoogle Scholar
  24. Kresse G, Joubert D (1999) From ultrasoft pseudopotentials to the projector augmented-wave method. Phys Rev B 59:1758–1775. CrossRefGoogle Scholar
  25. Li J, Wang H, Hu J, Wu R Q (2016) Search for giant magnetic anisotropy in transition-metal dimers on defected hexagonal boron nitride sheet. J Chem Phys 144(20):204,704. CrossRefGoogle Scholar
  26. Loth S, Baumann S, Lutz CP, Eigler DM, Heinrich AJ (2012) Bistability in atomic-scale antiferromagnets. Science 335(6065):196–199. CrossRefGoogle Scholar
  27. Meier F, Zhou L, Wiebe J, Wiesendanger R (2008) Revealing magnetic interactions from single-atom magnetization curves. Science 320(5872):82–86. CrossRefGoogle Scholar
  28. Mermin N D (1965) Thermal properties of the inhomogeneous electron gas. Phys Rev 137:A1441–A1443. CrossRefGoogle Scholar
  29. Muñoz-Navia M, Dorantes-Dávila J, Respaud M, Pastor G M (2009) Theoretical study of the magnetic moments and anisotropy energy of corh nanoparticles. Eur Phys J D 52(1):171–174. CrossRefGoogle Scholar
  30. Muñoz-Navia M M, Dorantes-Dávila J, Zitoun D, Amiens C, Jaouen N, Rogalev A, Respaud M, Pastor G M (2009) Tailoring the magnetic anisotropy in corh nanoalloys. Appl Phys Lett 95(23):233,107. CrossRefGoogle Scholar
  31. Panizon E, Ferrando R (2016) Strain-induced restructuring of the surface in core@shell nanoalloys. Nanoscale 8:15,911–15,919. CrossRefGoogle Scholar
  32. Parr R G, Yang W (1989) Density-functional theory of atoms and molecules. Oxford University Press, Oxford, pp 186–194Google Scholar
  33. Perdew J P (1991) Unified theory of exchange and correlation beyond the local density approximation. In: Ziesche P, Eschrig H (eds) Electronic structure of solids 91’, vol 17. Akademie Verlag, Berlin, pp 11–20Google Scholar
  34. Pianet V, Urdampilleta M, Colin T, Clérac R, Coulon C (2016) Magnetic tetrastability in a spin chain. Phys Rev B 94:054,431. CrossRefGoogle Scholar
  35. Rau IG, Baumann S, Rusponi S, Donati F, Stepanow S, Gragnaniello L, Dreiser J, Piamonteze C, Nolting F, Gangopadhyay S, Albertini OR, Macfarlane RM, Lutz CP, Jones BA, Gambardella P, Heinrich AJ, Brune H (2014) Reaching the magnetic anisotropy limit of a 3d metal atom. Science 344(6187):988–992. CrossRefGoogle Scholar
  36. Rossi G, Ferrando R, Mottet C (2008) Structure and chemical ordering in copt nanoalloys. Faraday Discuss 138:193–210. CrossRefGoogle Scholar
  37. Ruiz-Díaz P, Stepanyuk V S (2014) Effects of surface charge doping on magnetic anisotropy in capping 3d/5d(4d) multilayers deposited on highly polarizable substrates. J Phys D Appl Phys 47(10):105,006. CrossRefGoogle Scholar
  38. Ruiz-Díaz P, Dasa TR, Stepanyuk VS (2013) Tuning magnetic anisotropy in metallic multilayers by surface charging: an ab initio study. Phys Rev Lett 110:267,203. CrossRefGoogle Scholar
  39. Ruiz-Díaz P, Stepanyuk O V, Stepanyuk V S (2015) Effects of interatomic coupling on magnetic anisotropy and order of spins on metallic surfaces. J Phys Chem C 119(46):26,237–26,241. CrossRefGoogle Scholar
  40. Sahoo S, Hucht A, Gruner M E, Rollmann G, Entel P, Postnikov A, Ferrer J, Fernández-Seivane L, Richter M, Fritsch D, Sil S (2010) Magnetic properties of small Pt-capped Fe, Co, and Ni clusters: a density functional theory study. Phys Rev B 82:054,418. CrossRefGoogle Scholar
  41. Schnur S, Groß A (2011) Challenges in the first-principles description of reactions in electrocatalysis. Catal Today 165(1):129–137. Theoretical Catalysis for Energy Production and Utilization: from First Principles Theory to MicrokineticsCrossRefGoogle Scholar
  42. Serrate D, Yoshida Y, Moro-Lagares M, Kubetzka A, Wiesendanger R (2016) Spin-sensitive shape asymmetry of adatoms on noncollinear magnetic substrates. Phys Rev B 93:125,424. CrossRefGoogle Scholar
  43. Singha A, Donati F, Wäckerlin C, Baltic R, Dreiser J, Pivetta M, Rusponi S, Brune H (2016) Magnetic hysteresis in trimers on Cu(111). Nano Lett 16(6):3475–3481. CrossRefGoogle Scholar
  44. Strasser P, Koh S (2010) Lattice-strain control of the activity in dealloyed core-shell fuel cell catalysts. Nat Chem 2:454–460. CrossRefGoogle Scholar
  45. Sun S, Murray CB, Weller D, Folks L, Moser A (2000) Monodisperse fept nanoparticles and ferromagnetic fept nanocrystal superlattices. Science 287 (5460):1989–1992. CrossRefGoogle Scholar
  46. Wang D, Wu R, Freeman A J (1993) First-principles theory of surface magnetocrystalline anisotropy and the diatomic-pair model. Phys Rev B 47:14,932–14,947. CrossRefGoogle Scholar
  47. Yin S, Moro R, Xu X, de Heer W A (2007) Magnetic enhancement in cobalt-manganese alloy clusters. Phys Rev Lett 98:113,401CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V., part of Springer Nature 2018

Authors and Affiliations

  1. 1.Instituto de FísicaUniversidad Autónoma de San Luis PotosíSan Luis PotosíMéxico
  2. 2.CONACyT-Instituto de FísicaUniversidad Autónoma de San Luis PotosíSan Luis PotosíMéxico

Personalised recommendations