Innovation in Magnetic Data Storage Using Physical Deposition and Combinatorial Methods
Advances in data storage technologies and especially in disk drives (Figure 16.1(a)), are driven by discoveries and improvements in thin-film technologies. To produce a disk, numerous layers with different functions have to be deposited (see Figure 16.1(b)).1 Some layers have the purpose of storing the actual data “bit,” others are used to prime the correct crystallographic texture of the subsequent layers2 and yet others are used for corrosion protection or lubrication.3,4 Similarly the sensor or “head” that reads and writes the data is a complex thin-film structure as well.5-7 In order to further fine-tune these structures, it is important to be able to rapidly screen many different material sets and also to create transfer functions between different levels of parameters, so that it is possible to calculate the response and optimize the systems at a higher level. For example, it is important to be able to predict the coercivity as a function of alloy composition. At yet another level, it is important to predict the signal decay rate (Figure 16.1(c)), based on coercivity as well as other parameters.8,9 Hence, transfer functions and rapid screening of suitable thin-film combinations are important for the development of tomorrow’s disk drives.