Retarded Modes of Lateral Ferromagnetic/Ferromagnetic Superlattice

Abstract:

In this paper，we calculated the retarded modes of semi-infinite lateral ferromagnetic/ ferromagnetic superlattice with the effective medium theory. Take the Co/Ni system surface modes and bulk modes for the superlattice as the example and found some interesting properties which different from the lateral ferromagnetic/nonmagnetic superlattice. Lateral magnetism/magnetism superlattice have some complex retarded modes which are very common systems，changing the ratio of the superlattice ferromagnetism layer thickness so that two branches of surface modes frequency and bulk modes frequency band can be adjusted consequently. This tailoring effect is related to the two ferromagnetism layers saturation magnetization values. But the two saturation magnetization values are quite different than each other. If the difference between the tow values is large, the tailoring effect of f1 is more obvious. When the saturation magnetization value of the second ferromagnetic medium is approach to zero, this system will become magnetism/non-magnetism superlattice. If in Maxwell equation ε=0, the retarded modes will transite to ferromagnetic/ferromagnetic superlattice magnetostatic modes.

• Periodical: Applied Mechanics and Materials (Volume 151)
• Pages: 52-56
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.151.52
• Online since: January 2012
• Authors: Xiao Hua Liu, Yan Fen Liu, Jing Hui Liu, Zhi Zhang Song, Jian Jun Li
• Keywords: Effective-Medium Theory, Ferromagnetic/Ferromagnetic Superlattice, Retarded Modes, Spin Spectrum

References

[1] Jiang J J, Zhang S J, Liu Y, Effect of frustration on spin-wave excitation of the quasi-one-dimensional antiferromagnetic chain with asymmetrical sublattices,J. Acta Phys. sin. 55(2006) 4888.

DOI: 10.7498/aps.55.4888

[2] Liu F L, Liu F M, Derivation of magnetic polaritons dispersion equation by the antiferromagnetic film in Otto configuration , Journal of Beijing Institute of Machinery, J. 02(2001)6-9.

[3] Han Z Q , A model of microwave loss due to spin wave resonance in grain surface layers, Acta Phys. sin. J. 48 (1999) 291.

DOI: 10.7498/aps.48.291

[4] Yun G H, Yan J H, Ban S L. The effect of anisotropic field at two surfaces on spin-wave eigenmodes, J. Phys. Rev, B46(1992)12045.

[5] Yun G H, Yan J H, Ban S L, The dispersion relations of the spin waves in a A～B ferromagnetic bilayer system, J. Surf. Sci. 318(1994)177.

[6] Qiao H, Zi J, Xu Zh Zh, Zhang K M, Band structure of Si/Ge strained layer superlattice, J. Acta Phys. sin 42 (1993) 1317.

DOI: 10.7498/aps.42.1317

[7] Tang Ch H, Cai M Q, Yin Zh, Zh M Sh, Electronic band structure of ferroelectric SrBi2Nb2O9, J. Acta Phys. sin 53( 2004) 2931.

[8] Lu Sh Ch, Wang X Zh, D.R. Phase transition of a periodically diluted ising magnet, J. Tilley Phys. Rev. B55 (1997) 12402.

[9] Wang X Zh, D.R., Effects of eddy current on surface retarded modes of a lateral antiferro- magnet, J. Tilley, Phys. Rev. B52(1995)13353.

[10] J. Barnas, Magnetization dynamics in a magnetic tunnel junction due to spin tra-nsfer torque in the presence of interlayer exchange coupling,J. Phys: Condens. Matter, J. 34 (1990)7173.

DOI: 10.1109/tmag.2011.2108643

[11] N.S. Almeida D.R., Magnon spectrum of a uniaxial antiferromagnet with a general direction  of the applied field, J. Tilley, Sol. State Comms 73 (1990)23.

[12] Zhu R H, Jia Ch, Wang, X Zh , Magnetostatic modes of a lattaral ferromagnetic/ferromag- netic superlattice, J. Phys. Lett. A7 (2006) 355.