In this paper, a heat transfer model has been developed and employs method of Green function (heat source
method) to calculate the temperature distribution in the magnetic film by using ATM tip transferring heat. The
results indicate that the temperature in a magnetic film is relative to the diameter of the tip and the power of the
laser pulse. Specifically, the power of laser pulse has a critical point threshold in hybrid recording by using
The FePt single layer films with different thickness were deposited by RF magnetron sputtering on glass and Corning glass substrates, and the L10-FePt films were obtained after the as-deposited samples were subjected to vacuum annealing using different cooling processes. It costs 7 hours for the temperature to decrease from 550 to the room temperature during the natural cooling process, however it just costs 1.5 hours during the fast cooling process.Results show that after annealed at for 1h, the perpendicular coercivity of the FePt single layer films decreases with the increasing of FePt layer thickness, and the FePt 15nm film exhibits a high perpendicular coercivity of 8308 Oe and a low in-plane coercivity of 5141 Oe, which suggests that the film exhibits a high perpendicular anisotropy. The FePt films with nature cooling can obtain larger Mr/Ms values than that with fast cooling.
Pt and Ag underlayers with rough surface structure have been prepared onto glass slides by rf magnetron sputtering and
the effects of rough underlayers on the magnetic properties of TbFeCo films have been investigated. It was found that
rough Pt or Ag underalyers will increase the coercivity, the saturation magnetization and the Kerr rotation angle,
enhance the temperature dependence of magneto-optical characteristics. These results can be explained with the pinning
effects introduced by rough interfaces and the decrease of the exchange interaction between Tb atom and transition metal
atom. A saturation magnetization of 125emu/cm3 and a coercivity of 8.6kOe of Tb21Fe69Co10/Pt at room temperature
could be obtained, doping of the LRE elements such as Sm and Nd could increase the Ms of TbFeCo films with rough
underlayers. These films become a candidate for high -density hybrid recording media.
A self-ordered hexagonal array of nanopores has been fabricated by anodizing a thin film of Al on glass and
subsequently the magnetic properties of TbFeCo on this templates were studied. We carried out anodic oxidation of a
sputtered Al film at the anodic voltage in the range of 10-30 V and temperature in the range of 5-40 degrees C, and found that the
density of the nanohole arrays increased with the decrease in anodization voltage and temperature. On the other hand,
hole diameter decreased with the decrease in anodic voltage and temperature . Then TbFeCo was deposited onto this
porous array by sputtering with a thickness of around 90 nm and subsequently was overcoated with 10 nm SiN for the
protection from surface oxidation. The TbFeCo deposited on this porous layer shows complete perpendicular anisotropy
and the AAO template can promot the growth of the microcolumnar structure in TbFeCo films. The coercivity increased
with the decrease of hole diameter. The coercivity of the TbFeCo deposited on the porous array with a mean hole
diameter of around 15 nm is 5.6 kOe and larger than that on bare glass, but the squareness ratio gets poorer than that on
bare glass. Experience and simulation indicate that the magnetization reversal mode follows the Stoner-Wohlfarth .
The minimax optimization method is applied broadly to industrial design, agricultural test, automation, economy and so on. In the field of magnetic recording, we utilize it in determining optimal fabricating conditions of recording thin film media. In the procedure of thin film fabrication, the coercivity, the remenance- hickness product and the squareness ratio of magnetic thin film are considered as multiple-objective functions of these parameters: element composition, atmosphere pressure, substrate temperature, post-annealing temperature and thin film thickness. The optimal fabricating conditions and high performance of CoCrPt thin film are obtained using the minimax optimization based on a series of experiments and data. The coercivity of CoCrPt thin film is up to 3523Oe; the remenance-thickness product is up to 1.75 memu/cm2; and the squareness ratio is up to 0.83. The results show that the minimax optimization method can improve the fabricating conditions of recording thin film and is helpful for a short path of achieved high performance of CoCrPt thin film.