fe49co33ni18 nanowire arrays (175 nm in diameter and lengths ranging from 5 to 32μm) were fabricated into nanopores of hard-anodized aluminum oxide templates using pulsed ac electrodeposition technique. hysteresis loop measurements indicated that increasing the length decreases coercivity and squareness values (from 274 oe and 0.58 to200 oe and 0.105, respectively), indicating the increase in m...

Nanowire arrays have typical distributions of coercive and interaction fields, as revealed in experiments by means of the first-order reversal curve (FORC) method. In an axial applied field, each nanowire is subjected to a state dependent interaction field created by all wires from the array, which strongly influences the switching fields. A mean field model based on Preisach-Krasnosel'skii-Pok...

The first-order reversal curve (FORC) method is a macroscopic measurement technique that can be used to extract quantitative and microscopic properties of hysteretic systems. Using magnetic transmission x-ray microscopy (MTXM), local element-specific FORC measurements are performed on 20 nm thick film CoTb. FORCs measured with reveal step-by-step domain evolution under the field cycling protoco...

First-order reversal curve (FORC) diagrams provide a sensitive means of probing subtle variations in hysteresis behaviour, and can help advance our understanding of the mechanisms that give rise to hysteresis. In this paper, we use FORC diagrams to study hysteresis mechanisms in multi-domain (MD) particles. The classical domain wall (DW) pinning model due to Néel [Adv. Phys. 4 (1955) 191] is a ...

Relative abundance of magnetite originated from magnetotactic bacteria (magnetofossils) in sediments may influence relative paleointensity (RPI) estimations the geomagnetic field, as some studies reported an inverse correlation between RPI and ratio anhysteretic remanent magnetization susceptibility to saturation isothermal (kARM/SIRM), a proxy proportion biogenic terrigenous magnetic minerals ...

First-order reversal curve (FORC) measurements are a powerful tool to study magnetization processes and interactions in heterogeneous systems with broad coercivity distributions. In NdFeB hard magnets an additional soft magnetic component is often observed possibly originating from damaged surface grains. Here we use FORC the these permanent at different temperatures between 50 350 K. The measu...

Formins are highly conserved regulators of cytoskeletal organization and share three regions of homology: the FH1, FH2 and FH3 domains. Of the nine known formin genes or pseudogenes carried by Dictyostelium, forC is novel in that it lacks an FH1 domain. Mutant Dictyostelium lacking forC (DeltaforC) grew normally during the vegetative phase and, when starved, migrated normally and formed tight a...

Last year's Nobel Prize in Physics has showcased the vibrant research on magnetic nanostructures. Such artificially structured materials often exhibit novel and tunable properties as their physical dimensions become comparable to certain characteristic length scales. In this talk I will illustrate a variety of custom-designed magnetic nanostructures and highlight our recent studies of the magne...