DOI QR코드

DOI QR Code

Amorphous Cr-Ti Texture-inducing Layer Underlying (002) Textured bcc-Cr alloy Seed Layer for FePt-C Based Heat-assisted Magnetic Recording Media

  • Jeon, Seong-Jae ;
  • Hinata, Shintaro ;
  • Saito, Shin
  • Received : 2015.11.21
  • Accepted : 2016.03.14
  • Published : 2016.03.31

Abstract

$Cr_{100-x}Ti_x$ amorphous texture-inducing layers (TIL) were investigated to realize highly (002) oriented $L1_0$ FePt-C granular films through hetero-epitaxial growth on the (002) textured bcc-$Cr_{80}Mn_{20}$ seed layer (bcc-SL). As-deposited TILs showed the amorphous phase in Ti content of $30{\leq}x(at%){\leq}75$. Particularly, films with $40{\leq}x{\leq}60$ kept the amorphous phase against the heat treatment over $600^{\circ}C$. It was found that preference of the crystallographic texture for bcc-SLs is directly affected by the structural phase of TILs. (002) crystallographic texture was realized in bcc-SLs deposited on the amorphous TILs ($40{\leq}x{\leq}70$), whereas (110) texture was formed in bcc-SLs overlying on crystalline TILs (x < 30 and x > 70). Correlation between the angular distribution of (002) crystal orientation of bcc-SL evaluated by full width at half maximum of (002) diffraction (FWHM) and a grain diameter of bcc-SL indicated that while the development of the lateral growth for bcc-SL grain reduces FWHM, crystallization of amorphous TILs hinders FWHM. $L1_0$ FePt-C granular films were fabricated under the substrate heating process over $600^{\circ}C$ with having different FWHM of bcc-SL. Hysteresis loops showed that squareness ($M_r/M_s$) of the films increased from 0.87 to 0.95 when FWHM of bcc-SL decreased from $13.7^{\circ}$ to $3.8^{\circ}$. It is suggested that the reduction of (002) FWHM affects to the overlying MgO film as well as FePt-C granular film by means of the hetero-epitaxial growth.

Keywords

amorphous Cr-Ti texture inducing layer;bcc-Cr alloy seed layer;lateral grain growth;hetero-epitaxial growth;$L1_0$ FePt-C granular film;angular distribution of c-axis

References

  1. M. H. Kryder, E. C. Gage, T. W. McDaniel, W. A. Challener, R. E. Rottmayer, G. Ju, Y.-T. Hsia, and M. F. Erden, Proc. IEEE 96, 1810 (2008). https://doi.org/10.1109/JPROC.2008.2004315
  2. A. Q. Wu, Y. Kubota, T. Klemmer, T. Rausch, C. Peng, Y. Peng, D. Karns, X. Zhu, Y. Ding, E. K. C. Chang, Y. Zhao, H. Zhou, K. Gao, J.-U. Thiele, M. Seigler, G. Ju, and E. Gage, IEEE Trans. Magn. 49, 779 (2013). https://doi.org/10.1109/TMAG.2012.2219513
  3. X. Wang, K. Gao, H. Zhou, A. Itagi, M. Seigler, and E. Gage, IEEE Trans. Magn. 49, 686 (2013). https://doi.org/10.1109/TMAG.2012.2221689
  4. Seong-Jae Jeon, Shintaro Hinata, Shin Saito, and Migaku Takahashi, J. Appl. Phys. 117, 17A924 (2015). https://doi.org/10.1063/1.4919225
  5. Byung-Joo Lee, Metall. Trans. A 24, 1919 (1993). https://doi.org/10.1007/BF02666327
  6. B. D. Cullity and S. R. Stork, Elements of X-ray Diffraction, Prentice Hall, New Jersey (2001) pp. 167-171.
  7. S. Wicht, V. Neu, L. Schultz, V. Mehta, S. Jain, J. Reiner, O. Mosendz, O. Hellwig, D. Weller, and B. Rellinghaus, J. Appl. Phys. 117, 013907 (2015). https://doi.org/10.1063/1.4905422
  8. J. Wang, S. Hata, Y. K. Takahashi, H. Sepehri-Amin, B.S.D.Ch.S. Varaprasad, T. Shiroyama, T. Schreflc, and K. Hono, Acta Mater. 91, 41 (2015). https://doi.org/10.1016/j.actamat.2015.03.007