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 Fe Al thin film, where local irradiation by a focused ion beam causes the formation of disordered and strongly ferromagnetic regions of A2 Fe Al . 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.
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http://dx.doi.org/10.1002/smll.201904738 | DOI Listing |
Neuroimage
January 2025
Department of Radiology, First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China.. Electronic address:
The human cerebral cortex is known for its hemispheric specialization, which underpins a variety of functions and activities. However, it is not well understood if similar lateralization exists within the deep gray matter nuclei, such as the basal ganglia (BG) and thalamus, and their associated arteries, including the lenticulostriate arteries (LSAs). To explore this, we analyzed images from 7T MRI scans of 40 healthy young individuals.
View Article and Find Full Text PDFJ Phys Condens Matter
January 2025
Institute of Engineering & Management, Department of Basic Science and Humanities, Institute of Engineering & Management, Salt Lake Electronics Complex, Sector V, Salt Lake, Kolkata 700091, India, University of Engineering & Management, University Area, Plot No. III, B/5, New Town Road, Action Area III, Newtown, Kolkata 700160, India, Calcutta, West Bengal, 700091, INDIA.
A magnetic vortex (MV) is one of the fundamental and topologically nontrivial spin textures in condensed matter physics. Magnetic vortices are usually the ground states in geometrically restricted ferromagnets with zero magnetocrystalline anisotropy. Magnetic vortices have recently been proposed for use in a variety of spintronics applications due to their resistance to thermal perturbations, flexibility in changing core polarity, simple patterning procedure, and potential uses in magnetic data storage with substantial density, sensors for the magnetic field, devices for logic operations, and other related fields.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Laboratory of Alzheimer's Neuroimaging and Epidemiology - LANE, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy.
Background: This study investigated microstructural features of the locus coeruleus to entorhinal cortex pathway (LC-EC) in relation to amyloid (A), tau (T), neurodegeneration (N) markers and cognitive impairment in memory clinic patients.
Method: 124 participants were recruited from the Geneva Memory Clinic (n=30 cognitively unimpaired - CU; n=80 MCI and n=14 dementia - CI) and underwent clinical assessment, 3T MRI scan including diffusion weighted imaging, amyloid PET, and tau PET. Diffusivity indices (fractional anisotropy - FA, mean, axial and radial diffusivities - MD, AxD, RD) were assessed in the LC-EC pathway using a probabilistic atlas.
Alzheimers Dement
December 2024
Neuroimage Analytics Laboratory and Glenn Biggs Institute Neuroimaging Core, Glenn Biggs Institute for Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, TX, USA.
Background: The location of proposed brain MRI markers of small vessel disease (SVD) might reflect their pathogenesis and may translate into differential associations with cognition. We derived regional MRI markers of SVD and studied: (i) associations with cognitive performance, (ii) patterns most likely to reflect underlying SVD, (iii) mediating effects on the relationships of age and cardiovascular disease (CVD) risk with cognition.
Method: In 891 participants from The Multi-Ethnic Study of Atherosclerosis, we segmented enlarged perivascular spaces (ePVS), white matter hyperintensities (WMH) and microbleeds (MBs) using deep learning-based algorithms, and calculated white matter (WM) microstructural integrity measures of fractional anisotropy (FA), trace (TR) and free water (FW) using automated DTI-processing pipelines.
Background: Mild Cognitive Impairment (MCI) represents an intermediate stage between normal age-related cognitive decline and more severe degenerative conditions such as Alzheimer's disease. Understanding the differences between Early-MCI (EMCI) and Late-MCI (LMCI) is crucial to facilitate early diagnosis and future clinical interventions. This study employed free-water diffusion tensor imaging (FW-DTI) to explore the differences in white matter alterations between EMCI and LMCI.
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