A comparative study on the PMA behavior of 5-nm thick Co49Pt51 films grown at room temperature and at high temperature on glass substrates

作者：Tsai C Y; Saravanan P; Hsu Jen Hwa^*; Kuo C Y; Lin K F

来源：Journal of Magnetism and Magnetic Materials, 2014, 361: 7-11.

DOI：10.1016/j.jmmm.2014.02.062

• Magnetic film
• CoPt
• Perpendicular magnetic anisotropy
• Sputtering
• Spintronics

Co49Pt51 alloy films with strong perpendicular magnetic anisotropy (PMA) have been most often grown on either single crystal or glass substrates with deposition temperature of about 350 degrees C using Pt/Ru as an unclerlayer. In contrast, in this study, 5-nm thick Co49Pt51 alloy films with significant PMA were fabricated on glass substrates at room temperature (RT) using a combination of Ta and Pt underlayers. The structural and magnetic properties of the Co49Pt51 films obtained at RT (RT-CoPt) were compared with that of those produced by the conventional high-temperature route (HT-CoPt). The x-ray diffraction studies showed the evolution of highly textured Pt (111) peak accompanied by a CoPt (222) shoulder for the RT-CoPt films, similar to that of the HT-CoPt films. The microstructural studies revealed extremely smooth surface with root mean square roughness (R-rms) of 0.5 am for the RT-CoPt films, while the HT-CoPt films showed wavy surface with R-rms of 24 nm. The out-of-plane and in-plane hysteresis loops demonstrated the existence of strong PMA for both the RT-CoPt and HT-CoPt films. The estimated magnetic parameters for the RT-CoPt films such as scivarness ratio, SQR (0.96), perpendicular coercivity, H-c perpendicular to (822 Oe) and magneto crystalline anisotropy constant, K-u (64 x 10(6) erg/cm(3)) was found to be comparable to that of those obtained with the HT-CoPt films (SQR=0.96, H-c perpendicular to = 1810 Oe and K-u = 7.1 x 10(6) erg/cm(3)).

• 出版日期2014-6