AVS 45th International Symposium
    Thin Films Division Tuesday Sessions
       Session TF-TuM

Invited Paper TF-TuM1
Thin Film Media Requirements in Ultrahigh Density Magnetic Recording

Tuesday, November 3, 1998, 8:20 am, Room 310

Session: Thin Films for Sensing and Data Storage
Presenter: D. Weller, IBM Almaden Research Center
Authors: D. Weller, IBM Almaden Research Center
A. Moser, IBM Almaden Research Center
Correspondent: Click to Email
Rapidly increasing areal densities and data rates in hard disk magnetic recording impose stringent requirements on media and head materials. An imminent problem is media instability, which results from superparamagnetic effects. These effects become measurable in thin film granular magnetic recording media in the thickness range of about 10 nm and below. They lead to sizeable magnetic viscosity (logarithmic magnetization decay as function of measurement time) and to a write pulse width dependent coercivity. Examples of the latter measurements over 10 magnitudes in time (5 ns to 50 s) will be presented for typical CoPtCr magnetic recording media of variable thickness and at variable temperatures. The results will be discussed in the context of Neel-Arrhennius based decay models and recent micromagnetic modeling calculations. The thermal stability problem has led to a surge in interest in novel materials and media schemes. These include conventional but higher anisotropy media, perpendicular media, self assembled particle arrays and patterned media. We will discuss these various approaches in the context of ultimately achievable areal densities.