Energy barriers in patterned media

Due to the fact that thermal activation aids in overcoming the energy barrier, the required field for reversal varies from instance to instance for the same island. This thermally induced switching field distribution can be used to determine the difference in energy barrier of magneticallyweak and strong islands. In chapter 3 an alloy aswell as twomultilayer structures are compared using this method. In chapter 4 the temperature dependence of the thermally induced switching field distribution is investigated. For archival purposes it is not the data capacity but the longevity of the data which is most relevant. When we want store information which will outlast the human race, the medium will have different requirements than a mediumused for everyday information storage. For a hard disk, aminimumrequired storage time of 10 years is acceptable, but for such an archival storage system, 1 million to 1 billion years is the relevant timescale. In chapter 5 a storage system has been investigated with high energy barriers which should make data storage for such timescales possible.