The Determination of Flash Temperature in Intermittent Magnetic Head/Disk Contacts Using Magnetoresistive Heads: Part II—Experimental Investigation

Abstract

The flash temperature during intermittent head/disk contacts was measured using specially fabricated magnetoresistive heads. Microasperities were intentionally created on disk substrates, and ZrO2 was sputtered on disc surfaces as overcoat. It was found that with a disk spinning speed of 20 m/s, flash temperature could reach 50 to 100°C for transient contact (head was moving in disk radial direction), but less than 40°C for dwell on track contact (head was stationary). The contact times were in the range from submicroseconds to several microseconds, contact widths on the order of several micrometers, and temperature sensitivity coefficients in the range from 0.15 to 0.7 for a 2.5–μ high magnetoresistive sensor.