Grains help solve this problem because each grain is in theory a single magnetic domain (though not always in practice). This means that the magnetic domains cannot grow or shrink to form spikes, and therefore the transition width will be on the order of the diameter of the grains. Thus, much of the development in hard drives has been in reduction of grain size.
Grains help solve this problem because each grain is in theory a single magnetic domain (though not always in practice) This means that the magnetic domains cannot grow or shrink to form spikes and therefore the transition width will be on the order of the diameter of the grains Thus much of the development in hard drives has been in reduction of grain size