Patent ID: 7339764
Filing Date: 2008-03-04
Classification: G11B

Abstract:
1. A method of designing a patterned magnetic recording medium comprising a magnetic film with perpendicular magnetic anisotropy which is patterned into dots, comprising steps of: setting values to dot pattern periods P setting an initial value to a saturation magnetization M finding a dot size “a” in the x-direction and a nucleation field for magnetization reversal H where k B is the Boltzmann constant, T is an absolute temperature, and γ is a ratio of the dot size in the y-direction to the dot size in the x-direction; finding an inclination α of a perpendicular M-H loop of the magnetic dot with a shape of (a, γa, t) in accordance with the formula given below: where N d is a perpendicular demagnetizing factor of the magnetic dot, and ΔH c is a distribution broadening of a coercivity H c in the patterned magnetic recording medium, and estimating the coercivity judging whether the saturation field H