Size-dependent reversal of grains in perpendicular magnetic recording media measured by small-angle polarized neutron scattering

Abstract

Polarized small-angle neutron scattering has been used to measure the magnetic structure of a CoCrPt–SiOx thin-film data storage layer, contained within a writable perpendicular recording media, at granular (<10 nm) length scales. The magnetic contribution to the scattering is measured as the magnetization is reversed by an external field, providing unique spatial information on the switching process. A simple model of noninteracting nanomagnetic grains provides a good description of the data and an analysis of the grain-size dependent reversal provides strong evidence for an increase in magnetic anisotropy with grain diameter.

Synthesis and characterization of Co2FeAl nanowires

“…The misaligned grains with least energy barrier to reversal, which depends on the shape and crystallographic anisotropy, volume, easy axis orientation of the grain with respect to external field and interaction among grains, will be switched initially along the external field direction. 18,19 As temperature is increased, more grains will be switched in the direction of the field depending upon the magnitude of the field. Hence, the magnetization starts to increase because more domains are aligned in the direction of the external field, though each domain contribution to magnetization has decreased due to thermal demagnetization effect.…”

Developing Biotemplated Data Storage: Room Temperature Biomineralization of L10CoPt Magnetic Nanoparticles

“…[ 38 ] This observation of nanoscale regions with stable perpendicular magnetization is promising for the use of biotemplated CoPt in magnetic data storage, as a bit of information is usually recorded across a number of particles. [ 2 ] Thus, this ability of these surface biotemplated L1 0 CoPt MNPs to stably maintain their magnetic orientation at room temperature indicates that they could be developed for use in magnetic data storage applications.…”

“…Hard disks consist of layers of nanostructured magnetic materials that are able to reliably store bits of information. [ 2 ] High quality and uniformity are essential to ensure that the magnetic nano particles (MNPs) used to create recording surfaces can store data with high fi delity (i.e., low error rates). This is because MNPs with a uniform size, shape, and crystal structure have…”

Topographical length scales of hierarchical superhydrophobic surfaces

“…Length scales underpin many important areas of modern-day science and technology [1], with applications including the production of integrated circuits [2], information storage devices [3], display units [4], micro-electromechanical systems (MEMS) [5], miniaturized sensors [6], microfluidic devices [7], biochips [8], and photonic bandgap crystals [9]. For instance, the fundamental material properties of many useful size-dependent phenomena in optics, electronics, and magnetics displayed by nano-sized clusters of metals and semiconductors are governed by the length scales defining structure and organization [1].…”