Investigation of advanced nanomagnetic elements in nanomagnetic logic

Abstract

Nanomagnetic logic uses a magnetic phenomenon, which allows to encode and digitally process bits. To do this, elongated single domain ferromagnets are storing the binary “0” or “1” value in one of their two possible magnetic states. Due to dipolar magnetic coupling, two or more magnets can not only save, but process digital values, if the distance between those magnets is below a value dependent on the stray field. A big advantage of this technology is the elimination of stand-by power consumption and reduction of power for logic operations, compared to CMOS technology. In this thesis these concepts are reevaluated, and the properties of ring-shaped elements are investigated, which could broaden the horizon of this technique and bring new possibilities, as well as increase the data density by having more than two magnetic states. When nanoscale technology is considered, it conventionally uses to go hand in hand with a multi-step lithography process that consists of resist spinning, exposing to partially masked light and applying diverse layers of material which get structured by the previous steps. Here, the so-called focused electron beam induced deposition (FEBID) is used. This technique provides a direct-write fabrication, without the use of either photoresists or masks. Therefore, a precursor is injected into a vacuum chamber, where a focused electron beam is present, which allows to control geometric structuring of the deposition. Because the precursor gas Fe(CO)5 provides a high Fe content and good control over processed shapes it is used in this work.