Ultra-high coercivity small-grain FePt media for thermally assisted recording (invited)

Thermally assisted magnetic recording (TAR), a promising approach to extend data storage densities beyond 1 terabit/in.(2), requires high anisotropy granular magnetic media with small grains and a tight grain size distribution. We demonstrate sputtered chemically ordered granular L1(0) Fe45Pt45Ag10 media using carbon segregant on glass substrates. X-ray diffraction and transmission electron microscopy reveal high chemical ordering, an average grain size of < D > = 7.2 nm and a size distribution as low as sigma(D)=< D > 16%. Magnetic properties studied with a vibrating sample magnetometer show H-c = 4.8T, H-k > 9T, and K-u > 4.5 x 10(7) erg/cm(3). Drag testing of this media shows recording areal densities of 620 Gb/in.(2). (C) 2012 American Institute of Physics. [doi:10.1063/1.3680543]