Research article Special Issues

Direct observations of ferromagnetic and antiferromagnetic domains in Pt/Co/Cr2O3/Pt perpendicular exchange biased film

  • Received: 27 May 2015 Accepted: 16 November 2015 Published: 19 November 2015
  • By using focused soft X-rays, magnetic domain imaging based on X-ray magnetic circular dichroism (XMCD) measurements was performed on a Pt/Co/Cr2O3/Pt film that exhibits both perpendicular magnetic anisotropy and perpendicular exchange anisotropy. In the AC-demagnetized state, spatial distributions of the XMCD corresponding to the magnetic domains were clearly observed. In particular, ferromagnetic and antiferromagnetic magnetic domains were separately observed by tuning the photon energy to either the ferromagnetic Co L3 edge or the antiferromagnetic Cr L3 edge. The ferromagnetic domain pattern is similar to the ones previously reported for Co/Pt multilayers, and the ferromagnetic and antiferromagnetic domains are spatially coupled. The magnetization curve measured after cooling the sample, while maintaining the demagnetized state, exhibited positive and negative exchange biases simultaneously, which suggests that the exchange bias is determined on a domain-by-domain basis.

    Citation: Yu Shiratsuchi, Yoshinori Kotani, Saori Yoshida, Yasunori Yoshikawa, Kentaro Toyoki, Atsushi Kobane, Ryoichi Nakatani, Tetsuya Nakamura. Direct observations of ferromagnetic and antiferromagnetic domains in Pt/Co/Cr2O3/Pt perpendicular exchange biased film[J]. AIMS Materials Science, 2015, 2(4): 484-496. doi: 10.3934/matersci.2015.4.484

    Related Papers:

  • By using focused soft X-rays, magnetic domain imaging based on X-ray magnetic circular dichroism (XMCD) measurements was performed on a Pt/Co/Cr2O3/Pt film that exhibits both perpendicular magnetic anisotropy and perpendicular exchange anisotropy. In the AC-demagnetized state, spatial distributions of the XMCD corresponding to the magnetic domains were clearly observed. In particular, ferromagnetic and antiferromagnetic magnetic domains were separately observed by tuning the photon energy to either the ferromagnetic Co L3 edge or the antiferromagnetic Cr L3 edge. The ferromagnetic domain pattern is similar to the ones previously reported for Co/Pt multilayers, and the ferromagnetic and antiferromagnetic domains are spatially coupled. The magnetization curve measured after cooling the sample, while maintaining the demagnetized state, exhibited positive and negative exchange biases simultaneously, which suggests that the exchange bias is determined on a domain-by-domain basis.


    加载中
    [1] Hubert A, Schäfer R (2000) Magnetic Domains, New York, Springer, 395-520.
    [2] Wiesendanger R (1994) Scanning Probe Microscopy and Spectroscopy, Cambridge, Cambridge Press, 251-264.
    [3] MacCord J (2015) Progress in magnetic domain observation by advanced magneto-optical microscopy. J Phys D Appl Phys 48:333001. doi: 10.1088/0022-3727/48/33/333001
    [4] Spanke D, Dresselhaus J, Kinoshita T, et al. (1996) Element-specific magnetic domain imaging based on linear and circular magnetic dichroism in photoabsorption. J Electron Spectrosc Relat Phenom 78: 299-302. doi: 10.1016/S0368-2048(96)80084-3
    [5] Fischer P, Kim DH, Mesler BL, et al. (2007) Exploring nanomagnetism with soft X-ray microscopy. Surf Sci 601: 4680-4685. doi: 10.1016/j.susc.2007.05.054
    [6] Meiklejohn WH, Bean CP (1957) New magnetic anisotropy. Phys Rev 105: 904-913. doi: 10.1103/PhysRev.105.904
    [7] Nogués J, Schuller IK (1999) Exchange bias. J Magn Magn Mater 192:203-232. doi: 10.1016/S0304-8853(98)00266-2
    [8] Berkowitz AE, Takano K (1999) Exchange anisotropy - a review. J Magn Magn Mater 200: 552-570. doi: 10.1016/S0304-8853(99)00453-9
    [9] Dieny B, Speriosu VS, Parkin SSP, et al. (1991) Giant magnetoresistive in soft ferromagnetic multilayers. Phys Rev B 43: 1297-1300. doi: 10.1103/PhysRevB.43.1297
    [10] Mauri D, Siegmann HC, Bagus PS, et al. (1987) Simple model for thin ferromagnetic films exchange coupled to an antiferromagnetic substrate. J Appl Phys 62: 3047-3049. doi: 10.1063/1.339367
    [11] Malozemoff AP (1987) Random-field model of exchange anisotropy at rough ferromagnetic-antiferromagnetic interface. Phys Rev B 35: 3679-3682.
    [12] Malozemoff AP (1988) Mechanisms of exchange anisotropy (invited). J Appl Phys 63: 3874-3879. doi: 10.1063/1.340591
    [13] Duò L, Finazzi M, Ciccaci F (2010) Magnetic properties of antiferromagnetic oxide materials. Weinheim: Wiley-VCH, 301-339.
    [14] Scholl A, Stöhr J, Lüning J, et al. (2000) Observation of antiferromagnetic domains in epitaxial thin films. Science 287: 1014-1016. doi: 10.1126/science.287.5455.1014
    [15] Nolting F, Scholl A, Stöhr J, et al. (2000) Direct observation of the alignment of ferromagnetic spins by antiferromagnetic spins. Nature 405: 767-769. doi: 10.1038/35015515
    [16] Ohldag H, Regan TJ, Stöhr J, et al. (2001) Spectroscopic identification and direct imaging of interfacial magnetic spins. Phys Rev Lett 87: 247201. doi: 10.1103/PhysRevLett.87.247201
    [17] Arai K, Okuda T, Tanaka A, et al. (2012) Three-dimensional spin orientation in antiferromagnetic domain walls of NiO studied by X-ray magnetic linear dichroism photoemission electron microscopy. Phys Rev B 85: 104418. doi: 10.1103/PhysRevB.85.104418
    [18] Shiratsuchi Y, Noutomi H, Oikawa H, et al. (2012) Detection and in situ switching of unreversed interfacial antiferromagnetic spins in a perpendicular-exchange-biased system. Phys Rev Lett 109: 077202. doi: 10.1103/PhysRevLett.109.077202
    [19] He X, Wang Y, Wu N, et al. (2010) Robust isothermal electric control of exchange bias at room temperature. Nature Mater 9: 579-585. doi: 10.1038/nmat2785
    [20] Ashida T, Oida M, Shimomura N, et al. (2015) Isothermal electric switching of magnetization in Cr2O3/Co thin film system. Appl Phys Lett 106: 132407. doi: 10.1063/1.4916826
    [21] Toyoki K, Shiratsuchi Y, Kobane A, et al. (2015) Magnetoelectric switching of perpendicular exchange bias in Pt/Co/a-Cr2O3/Pt stacked films. Appl Phys Lett 106: 1624004.
    [22] Martin T, Anderson JC (1966) Antiferromagnetic domain switching in Cr2O3. IEEE Trans Magn 2: 446-449. doi: 10.1109/TMAG.1966.1065857
    [23] Shiratsuchi Y, Oikawa H, Kawahara S, et al. (2012) Strong perpendicular magnetic anisotropy at Co(111)/a-Cr2O3(0001) interface. Appl Phys Express 5: 043004. doi: 10.1143/APEX.5.043004
    [24] Muro T, Nakamura T, Matsushita T, et al. (2005) Circular dichroism measurement of soft X-ray absorption using helicity modulation of helical undulator radiation. J Electron Spectrosc Relat Phenom 144-147: 1101-1103. doi: 10.1016/j.elspec.2005.01.140
    [25] Kotani Y et al. in preparation.
    [26] Fischer P, Eimüller T, Schütz G, et al. (1999) Magnetic domain imaging with a transmission X-ray microscope. J Magn Magn Mater 198-199: 624-627. doi: 10.1016/S0304-8853(98)01210-4
    [27] Fischer P, Fadley CS (2012) Probing nanoscale behavior of magnetic materials with soft X-ray spectromicroscopy. Nanotechnol Rev 1: 5-15.
    [28] Ohtori H, Iwano K, Mitsumata C, et al. (2014) Visualization of magnetic dipolar interaction based on scanning transmission X-ray microscopy. J Phys Conf Series 502: 012010. doi: 10.1088/1742-6596/502/1/012010
    [29] Robertson MJ, Agostino CJ, N'Diaye AT, et al. (2015) Quantitative x-ray magnetic circular dichroism mapping with high spatial resolution full-field magnetic transmission soft x-ray spectro-microscopy. J Appl Phys 117: 17D145.
    [30] Kim GB, Song HJ, Shin HJ, et al. (2005) X-ray absorption spectroscopy in total electron yield mode of scanning photoelectron microscopy. J Electron Spectrosc Relat Phenom 148: 137-141. doi: 10.1016/j.elspec.2005.04.005
    [31] Nolle D, Weigand M, Schütz G, et al. (2011) High contrast magnetic and nonmagnetic sample current microcopy for bulk and transparent sample using soft X-rays. Microsc Microanal 17: 834-842.
    [32] Nolle D, Weigand M, Audehm P, et al. (2012) Note: Unique characterization possibilities in the ultra high vacuum scanning transmission x-ray microscope (UHV-STXM) “MAXYMUS” using a rotatable permanent magnetic field up to 0.22 T. Rev Sci Instrum 83: 046112. doi: 10.1063/1.4707747
    [33] Nakajima R, Stöhr J, Idzerda YU (1999) Electron-yield saturation effects in L-edge x-ray magnetic circular dichroism spectra of Fe, Co, and Ni. Phys Rev B 59:6421-6429. doi: 10.1103/PhysRevB.59.6421
    [34] Toyoki K, Shiratsuchi Y, Nakamura T, et al. (2014) Equilibrium surface magnetization of a-Cr2O3 studied through interfacial chromium magnetization in Co/a-Cr2O3 layered structures. Appl Phys Express 7: 114201. doi: 10.7567/APEX.7.114201
    [35] Astrov DN (1961) Magnetoelectric effect in chromium oxide. J Exptl Theoret Phys 40: 1035-1041.
    [36] Ji X, Pakhomov AB, Krishnan KM (2007) Asymmetric magnetic reversal of perpendicular exchange biased (Co/Pt)5/IrMn probed by magnetoresistance and magnetic force microscopy. J Appl Phys 101: 09E507.
    [37] Liu ZY, Li N, Zhang F, et al. (2008) Effect of magnetic field on domain-wall structures in two antiferromagnetically coupled Co/Pt multilayers. Appl Phys Lett 93: 032502. doi: 10.1063/1.2962990
    [38] Thole BT, Carra P, Sette F, et al. (1992) X-ray circular dichroism as a probe of orbital magnetization. Phys Rev Lett 68: 1943-1946. doi: 10.1103/PhysRevLett.68.1943
    [39] Carra P, Thole BT, Altarelli M, et al. (1993) X-ray circular dichrosism and local magnetic fields. Phys Rev Lett 70: 694-697. doi: 10.1103/PhysRevLett.70.694
    [40] Oura M, Nakamura T, Takeuchi T, et al. (2007) Degree of circular polarization of soft X-rays emitted from a multi-polarization-mode undulator characterized by means of magnetic circular dichroism measurements. J Synchrotron Rad 17: 483-486.
    [41] Andeev AF (1996) Macroscopic magnetic fields of antiferromagnets. J Exptl Theoret Phys 63: 758-762. doi: 10.1134/1.566978
    [42] Belashchenko KD (2010) Equilibrium magnetization at the boundary of a magnetoelectric antiferromagnet. Phys Rev Lett 105: 147204. doi: 10.1103/PhysRevLett.105.147204
    [43] Corliss LM, Hastings JM, Nathans R, et al. (1965) Magnetic structure of Cr2O3. J Appl Phys 36: 1099-1100. doi: 10.1063/1.1714118
    [44] Scholl A, Nolting F, Seo JW, et al. (2004) Domain-size-dependent exchange bias in Co/LaFeO3. Appl Phys Lett 85: 4085-4087. doi: 10.1063/1.1813633
    [45] Hoffmann A (2004) Symmetry driven irreversibilities at ferromagnetic-antiferromagnetic interfaces. Phys Rev Lett 93: 097203. doi: 10.1103/PhysRevLett.93.097203
  • Reader Comments
  • © 2015 the Author(s), licensee AIMS Press. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0)
通讯作者: 陈斌, bchen63@163.com
  • 1. 

    沈阳化工大学材料科学与工程学院 沈阳 110142

  1. 本站搜索
  2. 百度学术搜索
  3. 万方数据库搜索
  4. CNKI搜索

Metrics

Article views(5758) PDF downloads(1300) Cited by(17)

Article outline

Figures and Tables

Figures(6)  /  Tables(1)

/

DownLoad:  Full-Size Img  PowerPoint
Return
Return

Catalog