Title: Slider Dynamics for Magnetic Recording Sliders with Five Degrees of Freedom

Researcher: Jianfeng (John) Xu

Advisor: Prof. Frank Talke

Slider Dynamics for Magnetic Recording Sliders with Five Degrees of Freedom (DOF)

Magnetic recording sliders are expected to fly at a spacing of 3 to 5 nm above the disk in the near future. At spacing of less than 5 nm, intermittent contacts between the slider and the disk are likely to occur, leading to potential instabilities and failure of the head/disk interface. In this study, we investigate the motion of a slider during slider/disk contacts assuming five degrees of freedom, namely, vertical, pitch, roll, off-track, and down-track. In the experimental investigation, we have used three laser Doppler vibrometers to obtain the motion of the slider in the vertical, off-track and down-track direction, and a position sensitive detector to obtain the motion of the slider in the pitch and roll direction. The experimental results are discussed in terms of frequencies and amplitudes of the slider vibration during slider/disk contact.

We have also developed an analytical model for the same five degrees of freedom to determine the dynamics of slider motion. We have calculated the contact force, the adhesive force and the friction force using a sub-boundary layer ( SBL ) model. Comparison of experimental and numerical results was found to be in good agreement.

Fig. 1: 5 DOF measurement

Fig. 2: 5 DOF modeling