Focused-Ion-Beam-Assisted Magnet Fabrication and Manipulation for Magnetic Field Detection Applications

Abstract

The effect of synthesis conditions and . . . AbstractElectrochemically produced ZnO/metal rectifying (Schottky) junctions can exhibit consistent barrier heights and high rectifying ratios when prepared using optimized electrolyte pH (6.5) and applied voltage (≤-1.1 V vs. Ag/AgCl) conditions. An increase in soft breakdown for more acidic deposition electrolytes (pH 4) correlates with a diminished preferred orientation in the resulting ZnO electrodeposit. Forward-biased junctions exposed to increased relative humidities show increased current as a result of protonic conduction from water hydrolysis at the ZnO/air interface.At moderate to high relative humidities (50 − 85% RH), hydrophobic coatings improve the quality of the rectifying response by changing the wetting properties of the ZnO surface. Our findings suggest that electrodeposition, in conjunction with post-deposition surface coatings, can offer improved functionality for electron transport materials in wet or humid environments.

Nanomagnets with high shape anisotropy and strong crystalline anisotropy: perspectives on magnetic force microscopy

“…A Raith's Elphy Quantum routine changing both Ga + ion doses and ion beam currents is employed to complete the process. The technology for producing top-down nanomagnets is an extension of the FIB-milling-and-deposition process sequence previously reported by our group for micromagnet preparation and manipulation [1]. Current extension of technology comprises: (a) extraction of high-aspect-ratio nanomagnets from an NdFeB quarry and (b) sharpening of the nanomagnet tip down to 20 nm once attached to Si MEMS cantilevers.…”

“…Thus, we implemented a set-up consisting of the non-sharpened magnet integrated to a silicon cantilever and mounted in the AFM head, and a coil excited with DC current to observe cantilever deflections. Following this technique, we extracted magnetic moments (M = 2.1 × 10 5 A m −1 or J = 0.264 T) [1]. Due to the detection limit of the AFM set-up and the cantilever's mechanical constants, the technique finds its limits to micromagnet moment characterization.…”

“…A large enough magnetic anisotropy makes the direction of the macromoment in the nanomagnet sufficient stable to build non-volatile memories and highly sensitive magnetic force microscopy (MFM) systems. To address the rare-earth hard magnetism features, we previously developed a focused-ionbeam (FIB)-based technique to produce micromagnets [1]. Now, we develop and demonstrate an MFM application of FIB-milled rare-earth nanomagnets, where we replace conventional thin-film tips by our high shape anisotropy nanomagnets.…”

Magnetic imaging using geometrically constrained nano-domain walls

“…a lowered magnetic sensitivity. Thicker coatings, or hard magnetic materials, produce a larger magnetic moment 1,[16][17][18][19][20] that improves the magnetic sensitivity and the probe's resilience to magnetic perturbations, but at the cost of a dramatic increase of its interaction with the sample's magnetization and a loss in resolution due to the increased physical radius of the probe's apex.…”