Magnetoresistive head

J. Mallinson, Magnetoresistive Heads Fundamentals and Applications, Academic Press, San Diego, CA, 1997. 

Fig. 43 Schematic representation of digital magnetic recording system consisting of (1) inductive magnetic write head, (2) shielded MR (magnetoresistive) orGMR (giant magnetoresistive) head, and (3) magnetic recording medium (from Ref. 120 with permission from IBM Research and Development Division).

Smith, N., and P. Arnett. 2001. White-noise magnetization fluctuations in magnetoresistive heads. Applied Physics Letters 78(10) 1448-1450. 

The critical metallic components of advanced magnetic and magneto-optic (MO) storage devices— thin-film metal disks, inductive or magnetoresistive heads, and MO layers—are all susceptible to corrosion and each has been a subject of considerable study. Several review articles covering corrosion of magnetic-storage media may be found in the literature [135,136]. 

IBM, The Giant Magnetoresistive Head A giant leap for IBM Research , www.research.ibm.com/research/gmr.html. 

Luo et al. [1,153] used a slurry containing ultra-fine diamond (UFD) powders to polish the surface of HDD sliders. The powders are from 3 nm to 18 nm in diameter and 90 % around 5 nm. They are crystal and sphere-like [154]. The pH value of the slurry is kept in the range from 6.0 to 7.5 in order to avoid the corrosion of read-write heads, especially pole areas. A surface-active agent is added into the slurry to decrease the surface tension of the slurry to 22.5 Dyn/cm, and make it spread on the polish plate equably. An anti-electrostatic solvent is also added to the slurry to avoid the magnetoresistance (MR) head being destroyed by electrostatic discharge. The anion concentration of the slurry is strictly controlled in ppb level so as to avoid the erosion of magnetic heads as shown in Table 5. The concentration of UFDs in the slurry is 0.4 wt %. 

The electronic and magnetic properties of nanolayers are important in devices formed from electronic materials that are more conventional. We have already discussed quantum well lasers (see Chapter 8) and giant magnetoresistance (GMR) devices used for hard disk read heads (see Chapter 9). Quantum well lasers may be an important component of light-based computers. Other possibilities include magnets with unusual properties (Section 11.2). 

Figure 1. Integrated head with an inductive writer and a shielded magnetoresistive sensor used in present longitudinal recording.

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