High anisotropy L1/sub 0/ thin films for longitudinal recording

Nanocomposite CoPt:C films for extremely high-density recording

“…͑3͒ can be well satisfied even with dϭ4 nm (V ϭ6.4ϫ10 Ϫ20 cm 3 ). Large H c , which originate from the high K u value, were reported in CoPt bulk samples, 9 CoPt films, 10 CoPt nanoparticulates grown on quartz substrates, 11 and CoPt/Ag films. 12 For the purpose of forming small CoPt grains with weak exchange coupling, C would be an ideal isolation material between neighboring CoPt grains because there exist neither stable Co nor Pt carbides.…”

“…All as-deposited films are magnetically soft with H c less than 100 Oe. They most likely consist of disordered fcc CoPt, [9][10][11][12] which is the high-temperature phase, and/or amorphous CoPt in addition to C matrix. Since fct CoPt is the low-temperature phase, appropriate annealing leads to the transition from the fcc CoPt phase to the fct CoPt phase in CoPt:C films.…”

Orientation-controlled nonepitaxial L1 CoPt and FePt films

“…By controlling the thickness, composition, and annealing conditions, and/or depositing a proper underlayer, nearly perfect ͑001͒-oriented CoPt and FePt films can be obtained. Recently, L1 0 structured CoPt and FePt films, [1][2][3][4] CoPt and FePt based nanocomposite films 5,6 and FePt selfassembled nanoparticles 7 have attracted much attention. These high anisotropy materials show great potential for high-density magnetic recording because of their ability to achieve extremely small grain sizes.…”

“…7,8 Under normal growth conditions, the films often possess ͑111͒ preferred or random orientations. 1,4 For data-storage applications, it is desirable for the magnetic easy axis to orient either in the plane or perpendicular to the plane. 9 Hence, CoPt and FePt based films with ͑001͒ texture have an advantage over randomly or ͑111͒-oriented films.…”

Structural and magnetic properties of FePt:SiO2 granular thin films

“…Equiatomic FePt alloy thin films have attracted significant attention as possible high-density recording media [1][2][3][4] and high energy permanent magnets 5 because of their exceptional magnetic properties. As well known in the literature, the FePt binary alloy with a tetragonal L1 0 structure has a very high-anisotropy constant K 1 of 7ϫ10 7 erg/cc.…”