Self-assembled ferromagnetic cobalt/yttria-stabilized zirconia nanocomposites for ultrahigh density storage applications

Abstract

We report on a low-cost, innovative approach for synthesizing prepatterned, magnetic nanostructures, the shapes and dimensions of which can be easily tuned to meet requirements for next-generation data storage technology. The magnetic nanostructures consist of self-assembled Co nanodots and nanowires embedded in yttria-stabilized zirconia (YSZ) matrices. The controllable size and aspect ratio of the nanostructures allows the selection of morphologies ranging from nanodots to nanowires. Co nanowires show strong shape anisotropy and large remanence at 300 K. In contrast, Co nanodots display minimal effects of magnetocrystalline anisotropy and superparamagnetic relaxation above the blocking temperature. These prepatterned magnetic nanostructures are very promising candidates for data storage technology with an ultrahigh density of 1 terabit in(-2) or higher.

Out of plane superferromagnetic behavior of quasi two-dimensional Fe/Al2O3 multilayer nanocomposites

“…[3][4][5][6] On the other hand, the magnetic single-domain NPs ("superspins") are attractive for fundamental research in magnetism. 7,8 It is well known that highly diluted systems of ferromagnetic NPs (low filling factors, negligible interparticle interactions) exhibit superparamagnetic (SPM) properties, 9 described by the classic N eel-Brown model.…”

A Three Component Self‐Assembled Epitaxial Nanocomposite Thin Film

“…The low solubility of Cu in SrTiO 3 is presumed to have led to the formation of metallic Cu nanorods during growth in vacuum, as seen in other metal/ oxide systems. [15][16][17][18][19] The thermodynamic stability curve of Cu in terms of temperature and oxygen partial pressure [ 38 ] suggests that Cu becomes stable at an oxygen pressure below 1 × 10 −9 Torr at the deposition temperature, 650 °C. (In contrast, when STCu fi lms were grown in 0.1 mTorr of oxygen on STO substrate, a metallic Cu phase was not detected and the out-of-plane lattice parameter was 4.052 ± 0.004 Å suggesting that Cu was present in the STCu lattice.)…”

“…Nanocomposite fi lms have also been produced consisting of metallic nanostructures in an oxide matrix, including Co x Ni 1-x alloy nanowires, Co nanocrystals, nanofi bers, or Fe nanorods embedded in a CeO 2 , TiO 2 , perovskite or other oxide matrix. [15][16][17][18][19] For example, metallic Cu nanopillars or nanoparticles in an oxide matrix have been reported for plasmon resonance studies and for battery electrodes. [20][21][22] The vertical nanocomposite fi lms reported to date comprise two different phases, but additional functionalities and crosscoupling of properties may be possible in nanocomposites with more than two phases.…”

Self-organized ultrathin FePt nanowires produced by glancing-angle ion-beam codeposition on rippled alumina surfaces

“…As the thermal stability of magnetization orientation scales with the magnetic anisotropy constant K and magnetic grain volume V , ultrasmall bimetallic nanoparticles such as FePt and CoPt ('nanoalloys') have gained a lot of interest over the last decade, 1,[3][4][5][6][7][8][9][10][11] in particular due to the existence of chemically ordered phases (e.g., L1 0 structure) with very high uniaxial magnetocrystalline anisotropy. [13][14][15][16] Combining both shape and magnetocrystalline anisotropies, FePt and CoPt nanowires embedded in an insulating matrix are thus promising systems for prospective data storage applications. [13][14][15][16] Combining both shape and magnetocrystalline anisotropies, FePt and CoPt nanowires embedded in an insulating matrix are thus promising systems for prospective data storage applications.…”