Abstract
Exchange-coupled hard/soft magnetic materials have been widely studied during the last decade because of the prediction that these magnetic materials would have high energy-products. The soft and hard magnetic phases are exchange-coupled at particular grain sizes to give single-phase magnetic behavior. The grain size of the soft phase depends on the nature of the hard phase, and is usually around 10 nm. In this work, we studied soft phase exchange coupling with a hard phase at grain sizes of more than 10 nm to investigate the changes in magnetic properties, particularly the energy products, of nanocomposite hard/soft magnets. Bilayers of SmCo5/Fe were fabricated using magnetron sputtering on a 70-nm-Cr-buffered Si (100) substrate. The Fe thickness was varied up to 40 nm with 20 nm of SmCo5. Magnetic measurements were made using an alternating gradient magnetometer. In all the samples, the phases were strongly exchange-coupled with each other. The magnetization was found to increase and the coercivity to decrease with increasing Fe thickness. The energy product first increased and then decreased.
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References
Kneller E.F., Hawig R.: The exchange-spring magnet: a new material principle for permanent magnets. IEEE Trans. Magn. 27, 3588–3600 (1991)
Skomski R., Coey J.M.D.: Giant energy product in nanostructured two-phase magnets. Phys. Rev. B 48, 15812–15816 (1993)
Casoli F., Albertini F., Fabbrici S., Bocchi C., Nasi L., Ciprian R., Pareti L.: Exchange-coupled FePt/Fe bilayers with perpendicular magnetization. IEEE Trans. Magn. 41(10), 3877–3879 (2005)
Feng, Z.; Zhixin, H.; Zhigao, L.; Zengli, C.; Jihua, G.; Weiming, C.; Xiaofei, Y.: Effect of chromium interlayer on magnetic exchange coupling of SmCo/Cr/TbFeCo multilayer thin films. 26(3), 375–377 (2008)
Shahzad F., Siddiqi S.A., Zhou J.: Magnetic behaviour of Sm2Co7/Fe/Sm2Co7 nanocomposite trilayers with Cr and Ti additions. Chin. Phys. Lett. 26(3), 037701.1–037701.3 (2009)
Rong C.B., Nandwana V., Poudyal N., Liu J.P., Kozlov M.E., Baughman R.H., Ding Y., Wang Z.L.: Bulk FePt-based nanocomposite magnets with enhanced exchange coupling. J. Appl. Phys. 102, 023908.1–023908.7 (2007)
Zeng Q., Gabay A.M., Zhang Y., Hadjipanayis G.C.: Fully dense Sm-Co-Fe-Cu and Sm-Co-Fe-Ga nanocomposite magnets by hot compaction. IEEE Trans. Magn. 40(4), 2916–2918 (2004)
Zhang J., Zhang S.Y., Zhang H.W., Shen B.G., Li B.H.: Structure and magnetic properties of Sm x Co5/α-Fe (x = 0.65 − 1.3) prepared by mechanical milling and subsequent annealing. J. Appl. Phys. 89(5), 2857–2860 (2001)
Shahzad F., Siddiqi S.A., Im M.-Y., Avallone A., Fischer P., Hussain Z., Siddiqi I., Hellman F.: Layer resolved magnetization reversal study in SmCo5/Fe nanocomposite bilayers. Chin. Phys. B 19(3), 037504.1–037504.5 (2010)
Yan S.S., Barnard J.A., Xu F.T., Weston J.L., Zangari G.: Critical dimension of the transition from single switching to an exchange spring process in hard/soft exchange-coupled bilayers. Phys. Rev. B 64, 184403.1–184403.6 (2001)
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Shahzad, F., Siddiqi, S.A., Jing, X. et al. Variations in Magnetic Properties of SmCo5/Fe Exchange-Coupled Bilayers with Increasing Fe Thickness. Arab J Sci Eng 37, 251–254 (2012). https://doi.org/10.1007/s13369-011-0159-0
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DOI: https://doi.org/10.1007/s13369-011-0159-0