Surface Roughness Effects on Magnetization Reversal of Magnetic Ring Elements
The effect of surface roughness on magnetoresistance of permalloy ring structure is investigated. Microstructured permalloy rings with surface roughness varying from 4.2 to 21 nm were fabricated using electron beam lithography and a chemical etching process. It is found experimentally that the first and second nucleation fields decrease obviously with the surface roughness increasing, and the field range for the flux-closure state is not associated with surface roughness. The results indicate that surface roughness in permalloy ring structure is an important factor that influences the magnetic behaviors of the ring. This result can provide important information for future designs of ring-shaped magnetic devices.
A permalloy zigzag structure based magnetic bio-sensor
A magnetic fluid consisting of Fe3O4 magnetic nanoparticles is embedded inside cells by intracellular uptake. A micro-fabricated magnetic zigzag-shaped surface structure is studied for use as a biosensor. We have developed a MOKE magnetometer based methodology to measure the different hysteresis loop signals between cells with and without being placed on zigzag sensors. Adding the magnetic cells on the structure decreases the coercivity from the magneto-optical Kerr effect (MOKE) signal of zigzag magnetic thin films because of the magnetic properties of superparamagnetic nanoparticles. The magnetoresistance measurement observed is that the switching fields of the zigzag structure with magnetic cells are significantly increased compared to the case without cells in the hard axis of the external field applied.
The Primacy of Perception: And Other Essays on Phenomenological Psychology, the Philosophy of Art, History and Politics
The Primacy of Perception brings together a number of important studies by Maurice Merleau-Ponty that appeared in various publications from 1947 to 1961. The title essay, which is in essence a presentation of the underlying thesis of his Phenomenology of Perception, is followed by two courses given by Merleau-Ponty at the Sorbonne on phenomenological psychology. "Eye and Mind" and the concluding chapters present applications of Merleau-Ponty's ideas to the realms of art, philosophy of history, and politics. Taken together, the studies in this volume provide a systematic introduction to the major themes of Merleau-Ponty's philosophy.