Preparation of 3d Ferromagnetic Transition Metal Thin Films with Metastable bcc Structure on GaAs(100) Substrates

Abstract:

Ni, permalloy (Py: Ni - 20 at. % Fe), and Co films of 40 nm thickness are prepared on GaAs (100) single-crystal substrates at room temperature and 200 °C by magnetron sputtering. The growth behavior and crystallographic properties are studied. In early stages of film growth, metastable bcc single-crystals nucleate on the substrates for all the film materials. The crystal structure is stabilized through hetero-epitaxial growth. With increasing the thickness beyond 2 nm, the bcc structure starts to transform into fcc or hcp structure through atomic displacements parallel to the bcc {110} close-packed planes. The transformation orientation relationships are fcc {111}<10>, hcp {0001}<110> || bcc {110}<001>. The resulting Ni and Py films consist of a mixture of bcc and fcc phases, whereas the Co films involve an hcp phase in addition to the metastable bcc phase.

• Periodical: Key Engineering Materials (Volume 605)
• Pages: 478-482
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.605.478
• Online since: April 2014
• Authors: Mitsuru Ohtake*, Shigeyuki Minakawa, Masaaki Futamoto
• Keywords: Co, Epitaxial Growth, Magnetic Thin Film, Metastable bcc Structure, Ni, Permalloy

References

[1] X. -G. Zhang and W. H. Butler: Phys. Rev. B vol. 70 (2004), pp.172407-1–172407-4.

[2] S. Yuasa et al.: Appl. Phys. Lett. vol. 89 (2006), pp.042505-1–042505-3.

[3] J. P. Velev et al.: Phys. Rev. Lett. vol. 95 (2005), pp.216601-1–216601-4.

[4] C. S. Tian et al.: Phys. Rev. Lett. vol. 94 (2005), pp.137210-1–137210-4.

[5] Y. U. Idzerda et al.: Phys. Rev. Lett. vol. 62 (1989), p.2480–2483.

[6] S. J. Blundell et al.: J. Appl. Phys. vol. 73 (1993), p.5948–5950.

[7] E. Gu et al.: Phys. Rev. B vol. 52 (1995), p.14704–14708.

[8] Y. Z. Wu et al.: Phys. Rev. B vol. 57 (1998), p.11935–11938.

[9] M. Madami et al.: Sur. Sci. vol. 566–568 (2004), p.246–251.

[10] T. L. Monchesky and J. Unguris: Phys. Rev. B vol. 74 (2006), pp.241301-1–241301-4.

[11] M. Ohtake, Y. Nonaka, M. Futamoto, IEEE Trans. Magn. vol. 48 (2012), p.1589–1592.

[12] G. Wasserman: Arch. Eisenhuettenwes vol. 16 (1933), p.647–659.

[13] Z. Nishiyama: Sci. Rep. Tohoku Univ. vol. 23 (1934), p.638.