Deposition and properties of polycrystalline cobalt ferrite films for magneto-optical recording

摘要

Abstract: The polycrystalline cobalt ferrite films were deposited by dc-sputtering method from ferrite targets. These targets were conductive because of using of reduction atmosphere for time its preparation that allowed dc-sputtering. The magnetic and magneto-optical properties of these films have been investigated. The prepared Co$-0.07$/Fe$-2.3$/O$-4$/ polycrystalline films had perpendicular magnetic anisotropy, high coercivity (2 - 5 kOe) and good hysteresis loop squareness. It was established that perpendicular anisotropy constant and coercivity of films depends on substrate thermal expansion coefficient. The wavelength dependence of Faraday rotation $Theta$-F$/ is typical that for cobalt ferrite films and have two maximum: $Theta$-F$/ $EQ 2,7 deg/$mu@m within $lambda $EQ 0,5 - 0,53 $mu@m and $Theta$- F$/ $EQ 2,5 deg/$mu@m at $lambda $EQ 0,8 $mu@m, last presents the practical interest and is sufficiently high value. Magneto-optical figure of merit reaches 0,5 deg. at $lambda $EQ 0,63 $mu@m and 3,0 deg at $lambda $EQ 0.8 $mu@m. According to achieved results the polycrystalline cobalt ferrite Co$-0.7$/Fe$-2.3$/O$-4$/ films are a good candidate for a magneto-optical storage media.!11