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Quantum well States in Fe (100) Ultrathin Films Observed by Magneto-Optical Effect

Published online by Cambridge University Press:  03 September 2012

Yoshishige Suzuki
Affiliation:
Electrotechnical Laboratory, UMezono 1–1–4, Tsukuba, Ibaraki 305, Japan.
Toshikazu Katayama
Affiliation:
National Institute for Advanced Interdisciplinary Research, Higashi 1–1–4, Tsukuba, Ibaraki 305, Japan.
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Abstract

We report on the Magneto-optical Kerr rotation (<φ>K) spectra of ultrathin Fe films on Au or Ag (100) substrates and the φK oscillation due to interlayer thickness in Fe/Au/Fe sandwich films. In 3.5–4.5 eV, a new φK peak appears in the bcc-Fe (100) ultrathin films on the fcc-Au (100) surface and it shifts towards the higher energy side with increasing Fe layer thickness. The absolute value of eXy for 3Å (2ML) thick Fe layers is twice as large as that of bulk Fe at 3.7 eV. The thickness dependence of the transition energy of this new peak in the spectra is well explained by the concept of quantum well states in the Fe ultrathin layers, attributing the new transition to a transition from the majority spin Δ5 band ({px±i py), {dxz±i dyZ}; M=±l) to the Δ1 quantum well states (s, pz, dz2; M=0). The new peak is also observed in the Fe/Au (100) artificial superlattices. Using the εxy obtained experimentally for the Fe ultrathin films and the εxy of literature, we can reproduce the experimental φK spectra of the artificial superlattices by optical calculation. On the other hand, we cannot observe the same behavior for the ultrathin Fe films grown on a fcc-Ag (100) surface and covered by a Au (100) ultrathin film, although the εXy of Fe is different from that of the bulk and shows some structures in 2–3 eV. These structures around 2.5 eV are thought to be due to polarized Au atoms adjacent to an Fe layer.

An oscillation of φK as a function of interlayer thickness, d, was observed in photon energy region between about 2.5 and 3.8 eV for the Fe (6Å) /Au (dÅ) /Fe (6A) sandwiched film. The oscillation period was about 10Å (5ML) of Au. The oscillation is thought to be closely related with a formation of spin polarized quantum well states of Δ1 band in Au layers sandwiched by magnetic layers.

Type
Research Article
Copyright
Copyright © Materials Research Society 1993

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References

[1]. Baibich, M.N., Broto, J.M., Fert, A., Nguyen Van Dau, F., Ptroff, F., Eitenne, P., Creuzet, G., Friederich, A., and Chazelas, J., Phys. Rev. Lett., 61, 2472 (1988).Google Scholar
[2]. Perkin, S.S.P., More, N., and Roche, K.P., Phys. Rev. Lett., 64, 2304 (1990).Google Scholar
[3]. Fu, C.L., Freeman, A.J., and Oguchi, T., Phys. Rev. Lett., 54, 2700 (1985), andGoogle Scholar
Richter, Roy, Gay, J.G., and Smith, John R., 54, 2704 (1985).Google Scholar
[4]. Li, Chun, Freeman, A.J., and Jansen, H.J.F., Phys. Rev., B42, 5433 (1990).Google Scholar
[5]. Jonker, B.T., Walker, K.-H., Kisker, E., Prinz, G.A., and Carbone, C., Phys. Rev. Lett., 57, 142 (1986).Google Scholar
[6]. Himpsel, F.J., Phys. Rev. (B) 44, 5966 (1991).Google Scholar
[7]. Brookes, N.B., Chang, Y. and Johnson, P.D., Phys. Rev. Lett., 67, 354 (1991) andGoogle Scholar
Ortega, J.E. and Himpsel, F.J., Phys. Rev. Lett., 69, 844 (1992), J.E. Ortega and F.J. Himpsel, to be published in Phys. Rev. B.Google Scholar
[8]. Bader, S.D., J. Magn. Magn. Matt., 100. 440 (1991), and references in this report.Google Scholar
[9]. Bennett, W.R., Schwarzacher, W. and Egelhoff, W.F., Phys. Rev. Lett., 65, 3169 (1990)Google Scholar
[10]. Ferré, J., Pénissard, G., Marliere, C., Renard, D., Beauvillain, P., and Renard, J.P., Appl. Phys. Lett., 56, 1588 (1990).Google Scholar
[11]. Katayama, T., Awano, H., and Nishihara, Y., J. Phys. Soc. Jpn., 55, 2539 (1986), andGoogle Scholar
Katayama, T., Suzuki, Y., Awano, H., Nishihara, Y., and Koshizuka, N., Phys. Rev. Lett., 60, 1426 (1988), andGoogle Scholar
Sato, K., Kida, H., and Katayama, T., Jpn. J. Appl. Phys., 27, L237 (1988).Google Scholar
[12]. Suzuki, Y., Katayama, T., Sato, K., Yoshida, S. and Tanaka, K., Phys. Rev. Lett., 68, 3355 (1992).Google Scholar
[13]. Suzuki, Y., Katayama, T., Thiaville, A., Sato, K., Taninaka, M., and Yoshida, S., J. Magn. Magn. Matt., in print, Y. Suzuki and T. Katayama, To be published in Proc. of MORIS'92, [Supplement of J. Magn. Soc. Jpn (1993)], M. Hayashi, T. Katayama, Y. Suzuki, M. Taninaka, A. Thiaville, and W. Geerts, Proceedings of MML '92 Kyoto, to be published in J. Magn. Magn. Matt., T. Katayama, Y. Suzuki, M. Hayashi, and A. Thiaville, Proceedings of MML '92 Kyoto, to be published in J. Magn. Magn. Matt‥Google Scholar
[14]. Edwards, D.M., Mathon, J., Muniz, R.B., and Phan, M.S., Phys. Rev. Lett., 67, 493 (1991), andGoogle Scholar
Bruno, P. and Chappert, C., Phys. Rev. Lett., 62, 1602 (1991).Google Scholar
[15]. Smith, D.Y., J. Opt. Soc. Am., 66, 547 (1976).Google Scholar
[16]. Johnson, P. B. and Christy, R.W., Phys. Rev. B6, 4370 (1972).Google Scholar
[17]. Johnson, P.B. and Christy, R.W., Phys. Rev. B9, 5056 (1974), andGoogle Scholar
Krinchik, G.S. and Artem'ev, V.A., Zh. Eksp. Teor. Fiz., 52, 1901 (1967) [Sov. Phys. JETp 26, 1080 (1967)].Google Scholar
[18]. Argyres, P.N., Phys. Rev., 97, 334 (1955).Google Scholar
[19]. This can be easily derived assuming the virtural optical index of the whole system is not affected by an addition/substraction of one period of the layers.Google Scholar
[20]. Feil, H. and Haas, C., Phys. Rev. Lett., 58, 65 (1987).Google Scholar
[21]. Reim, W. and Schoenes, J., in Handbook of Ferromagnetic Materials, vol. 5, eds. Wohlfahrt, E.P. and Bushow, K.H.J. (North-Holland, Amsterdam, 1990), pp. 147153.Google Scholar
[22]. Eckardt, H., Fritsche, L., and Noffke, J., J. Phys. F: Mat. Phys., 14, 97 (1984), andGoogle Scholar
Lässer, R., Smith, N.V., and Benbow, R.L., Phys. Rev., B24, 1895 (1981).Google Scholar
[23]. Callaway, J. and Wang, C.S., Phys. Rev. B16, 2095 (1977).Google Scholar
[24]. Oppeneer, P.M., Mayrer, T., Sticht, J., and Kuber, J., Phys. Rev., B45, 10924 (1992).Google Scholar
[25]. , Schnatterrly, Phys. Rev. 183, 664, (1969).Google Scholar