Study of Magnetism of Two-Dimensional Ferromagnetic Graphene

Abstract:

In this paper, the magnetic properties of ferromagnetic graphene nanostructures, especially the dependence of the magnetism on finite temperature, are investigated by use of the many-body Green’s function method of quantum statistical theory. The spontaneous magnetization increases with spin quantum number, and decreases with temperature. Curie temperature increases with exchange parameter J or the strength K2 of single-ion anisotropy and spin quantum number. The Curie temperature TC is directly proportional to the exchange parameter J. The spin-wave energy drops with temperature rising, and becomes zero as temperature reaches Curie temperature. As J(p,q)=0, ω1=ω2, the spin wave energy is degenerate, and the corresponding vector k=(p, q) is called the Dirac point. This study contributes to theoretical analysis for pristine two-dimensional magnetic nanomaterials that may occur in advanced experiments.

• Periodical: Advanced Materials Research (Volume 601)
• Pages: 89-93
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.601.89
• Online since: December 2012
• Authors: Bin Zhou Mi, Yong Hong Xue, Huai Yu Wang, Yun Song Zhou, Xiao Lan Zhong
• Keywords: Ferromagnetic Graphene, Heisenberg Model, Magnetic Property, Many-Body Green’s Function Method

References

[1] Peierls, R. E. Quelques proprietes typiques des corpses solides. Ann. I. H. Poincare 5, 177-222 (1935).

[2] Landau, L. D. Zur Th eorie der phasenumwandlungen II. Phys. Z. Sowjetunion 11, 26-35(1937).

[3] Novoselov, K. S. et al., Science 306, 666-669(2004).

[4] Castro Neto, A. H. et al., Rev. Mod. Phys., Vol. 81, No. 1, 109-162(2009).

[5] Valentina Tozzini, and Vittorio Pellegrini, Phys. Rev. B 81, 113404 (2010).

[6] Pisani, L.; Chan, J. A.; Montanari, B.; Harrison, N. M. Phys. Rev. B 75, 064418-064426(2007).

[7] Topsakal,M.; Sevincli,H.; Ciraci,S. Appl. Phys. Lett. 92, 173118-173120(2008).

[8] Fernadez-Rossier, J.; Palacios, J. J. Phys. Rev. Lett. 99, 177204-177207(2007).

[9] Yan Wang, Yi Huang, You Song, Xiaoyan Zhang, Yanfeng Ma, Jiajie Liang, andYongsheng Chen, Nano Lett., 9(1), 220-224(2009).

[10] Huang,B.; Liu,F.; Wu,J.; Gu,B.L.; Duan,W. Phys. Rev. B 77, 153411-153414(2008).

[11] Choi,S.; Jeong B.W.; Kim,S.; Kim,G. J. Phys.: Condens. Matter, 20, 235220-235223(2008).

[12] Palacios J.J.; Fernadez-Rossier,J.; Brey, L. Phys. Rev. B 77, 195428-195441(2008).

[13] Yazyev, O. V.; Helm, L. Phys. Rev. B 75, 125408-125412(2007).

[14] Sevincli, H.; Topsakal, M.; Durgun, E.; Ciraci, S. Phys. Rev. B 77, 195434-195440(2008).

[15] Zanella, I.; Fagan, S. B.; Mota, R.; Fazzio, A. J. Phys. Chem. C 112, 9163-9167(2008).

[16] J. Zhou, Q. Wang, Q. Sun, X.S. Chen, Y. Kawazoe, and P. Jena, Nano Lett., 9(11) 3867-3870(2009).

[17] Yandong Ma, Ying Dai, Meng Guo, Chengwang Niu, Yingtao Zhu, and Baibiao Huang, Nano Lett. 6(2), 1695-1701 (2012).

[18] N. M. Mermin and H. Wagner, Phys. Rev. Lett. 17, 1133 (1966).

[19] Bin-Zhou Mi, Huai-Yu Wang, and Yun-Song Zhou, J. Magn. Magn. Mater. 322, 952-958(2010).

[20] Bin-Zhou Mi, Huai-Yu Wang, and Yun-Song Zhou, Phys. Status Solidi B 248 No. 5, 1280-1286 (2011).

[21] Wang Huaiyu, Green's Function in Condensed Matter Physics, Science Press and Alpha Science International Ltd. (Printed in China, 2012).

[22] P. Fröbrich and P. J. Kuntz, Physics Reports 432, 223-304 (2006).