NANOlab Center of Excellence literature database -- Query Results

“Strain Anisotropy and Magnetic Domains in Embedded Nanomagnets”. Nord M, Semisalova A, Kákay A, Hlawacek G, MacLaren I, Liersch V, Volkov OM, Makarov D, Paterson GW, Potzger K, Lindner J, Fassbender J, McGrouther D, Bali R, Small , 1904738 (2019). http://doi.org/10.1002/smll.201904738 Abstract: Nanoscale modifications of strain and magnetic anisotropy can open pathways to engineering magnetic domains for device applications. A periodic magnetic domain structure can be stabilized in sub‐200 nm wide linear as well as curved magnets, embedded within a flat non‐ferromagnetic thin film. The nanomagnets are produced within a non‐ferromagnetic B2‐ordered Fe60Al40 thin film, where local irradiation by a focused ion beam causes the formation of disordered and strongly ferromagnetic regions of A2 Fe60Al40. An anisotropic lattice relaxation is observed, such that the in‐plane lattice parameter is larger when measured parallel to the magnet short‐axis as compared to its length. This in‐plane structural anisotropy manifests a magnetic anisotropy contribution, generating an easy‐axis parallel to the short axis. The competing effect of the strain and shape anisotropies stabilizes a periodic domain pattern in linear as well as spiral nanomagnets, providing a versatile and geometrically controllable path to engineering the strain and thereby the magnetic anisotropy at the nanoscale. Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) Impact Factor: 8.643 Times cited: 2 DOI: 10.1002/smll.201904738 Additional Links: UA library record; WoS full record; WoS citing articles show.php?record=5376
“Confined Catalytic Janus Swimmers in a Crowded Channel: Geometry-Driven Rectification Transients and Directional Locking”. Yu H, Kopach A, Misko VR, Vasylenko AA, Makarov D, Marchesoni F, Nori F, Baraban L, Cuniberti G, Small 12, 5882 (2016). http://doi.org/10.1002/SMLL.201602039 Abstract: Self-propelled Janus particles, acting as microscopic vehicles, have the potential to perform complex tasks on a microscopic scale, suitable, e.g., for environmental applications, on-chip chemical information processing, or in vivo drug delivery. Development of these smart nanodevices requires a better understanding of how synthetic swimmers move in crowded and confined environments that mimic actual biosystems, e.g., network of blood vessels. Here, the dynamics of self-propelled Janus particles interacting with catalytically passive silica beads in a narrow channel is studied both experimentally and through numerical simulations. Upon varying the area density of the silica beads and the width of the channel, active transport reveals a number of intriguing properties, which range from distinct bulk and boundary-free diffusivity at low densities, to directional “locking” and channel “unclogging” at higher densities, whereby a Janus swimmer is capable of transporting large clusters of passive particles. Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) Impact Factor: 8.643 Times cited: 14 DOI: 10.1002/SMLL.201602039 Additional Links: UA library record; WoS full record; WoS citing articles show.php?record=4453

Abstract: Nanoscale modifications of strain and magnetic anisotropy can open pathways to engineering magnetic domains for device applications. A periodic magnetic domain structure can be stabilized in sub‐200 nm wide linear as well as curved magnets, embedded within a flat non‐ferromagnetic thin film. The nanomagnets are produced within a non‐ferromagnetic B2‐ordered Fe60Al40 thin film, where local irradiation by a focused ion beam causes the formation of disordered and strongly ferromagnetic regions of A2 Fe60Al40. An anisotropic lattice relaxation is observed, such that the in‐plane lattice parameter is larger when measured parallel to the magnet short‐axis as compared to its length. This in‐plane structural anisotropy manifests a magnetic anisotropy contribution, generating an easy‐axis parallel to the short axis. The competing effect of the strain and shape anisotropies stabilizes a periodic domain pattern in linear as well as spiral nanomagnets, providing a versatile and geometrically controllable path to engineering the strain and thereby the magnetic anisotropy at the nanoscale.

Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)

Impact Factor: 8.643

Times cited: 2

DOI: 10.1002/smll.201904738

Additional Links: UA library record; WoS full record; WoS citing articles

show.php?record=5376

Abstract: Self-propelled Janus particles, acting as microscopic vehicles, have the potential to perform complex tasks on a microscopic scale, suitable, e.g., for environmental applications, on-chip chemical information processing, or in vivo drug delivery. Development of these smart nanodevices requires a better understanding of how synthetic swimmers move in crowded and confined environments that mimic actual biosystems, e.g., network of blood vessels. Here, the dynamics of self-propelled Janus particles interacting with catalytically passive silica beads in a narrow channel is studied both experimentally and through numerical simulations. Upon varying the area density of the silica beads and the width of the channel, active transport reveals a number of intriguing properties, which range from distinct bulk and boundary-free diffusivity at low densities, to directional “locking” and channel “unclogging” at higher densities, whereby a Janus swimmer is capable of transporting large clusters of passive particles.