All articles starting with M

Magnetic soft robots

Magnetic soft robots are robots made of soft polymer embedded with magnetic particles, remotely bent and propelled by external magnetic fields; millimeter-scale and tether-free, they target biomedical uses like drug delivery.

Magnetic solid phase extraction

Magnetic solid phase extraction (MSPE), or magnetic dispersive solid-phase extraction, is a sample preparation technique in which magnetic adsorbents dispersed in a liquid sample capture target analytes, then are retrieved with an external magnet.

Magnetic spectrometer (nuclear physics)

A magnetic spectrometer is a nuclear physics instrument that uses magnetic fields to deflect and separate charged particles from nuclear reactions, measuring their momenta, energies, masses, and charges at a focal plane.

Magnetic stir bar

A magnetic stir bar, also called a stir bar or "flea", is a coated magnet spun by a stirrer base to mix liquids in a sealed vessel without any opening.

Magnetic storage

Magnetic storage, also called magnetic data storage, records digital data by magnetizing regions of a ferromagnetic material, chiefly in hard disk drives and magnetic tape.

Magnetic survey

A magnetic survey is a geophysical method that maps spatial variations in Earth's magnetic field to image subsurface geology, mineral deposits, and buried structures, measured in nanotesla.

Magnetic susceptibility

Magnetic susceptibility is a measure of how strongly a material becomes magnetized in an applied magnetic field, sorting substances into diamagnetic, paramagnetic, and ferromagnetic classes.

Magnetic tape

Magnetic tape is a storage medium of thin plastic ribbon coated with magnetic particles, used for audio, video, and digital data, first commercialized for sound in the 1930s.

Magnetic topological insulator

A magnetic topological insulator is a material combining a topological insulator's band structure with internal magnetic order, enabling the quantum anomalous Hall effect, observed in MnBi2Te4 up to 6.5 K.

Magnetic trap (atoms)

A magnetic trap for atoms is an arrangement of magnetic fields that confines laser-cooled neutral atoms in vacuum, and it enabled the first Bose-Einstein condensate of a dilute gas in 1995.

Magnetic trapping

Magnetic trapping confines neutral particles with magnetic moments, such as atoms, neutrons, and molecules, in a magnetic field minimum, enabling storage and evaporative cooling to degenerate gases first demonstrated with sodium atoms in 1985.

Magnetic tunnel junction

A magnetic tunnel junction (MTJ) is a nanoscale device of two ferromagnetic electrodes separated by a 1–2 nm insulating barrier, whose resistance depends on the electrodes' magnetic alignment.

Magnetic tweezers

Magnetic tweezers are a single-molecule force spectroscopy technique that stretches and twists biomolecules such as DNA using magnetic beads, tracking hundreds of molecules simultaneously with sub-nanometer precision.

Magnetic vector potential

The magnetic vector potential A is a vector field whose curl equals the magnetic field B. It is not unique, and the 1959 Aharonov-Bohm effect showed it has physical significance.

Magnetic vortex

A magnetic vortex is a spin texture in a ferromagnetic nanostructure, typically a thin-film disk, where in-plane magnetization curls to close flux lines around a small core pointing out of plane.

Magnetic Weyl semimetal

A magnetic Weyl semimetal is a topological semimetal in which magnetism breaks time-reversal symmetry, creating Weyl nodes; first proposed in 2011 and realized in Co₃Sn₂S₂ in 2019.

Magnetic wheel

A magnetic wheel is a wheel containing a permanent magnet that adheres to steel surfaces, letting robots climb walls and inspect tanks, ship hulls, and pipes without suction cups.

Magnetic white dwarf

A magnetic white dwarf is a white dwarf whose surface carries a detectable magnetic field, from thousands up to hundreds of millions of gauss; about 20 to 25 percent of nearby white dwarfs are magnetic.

Magnetic wormhole

A magnetic wormhole is a laboratory device built from metamaterials that transfers a static magnetic field between two points, undetectable from outside, first demonstrated in Barcelona in 2015.

Magnetic-core memory

Magnetic-core memory, also called ferrite core memory, stores each bit in a magnetized ferrite ring; it dominated computer memory from the mid-1950s to the early 1970s.

Magnetically actuated soft metamaterials

Magnetically actuated soft metamaterials are architected soft polymers embedded with magnetic particles that change shape or properties under an external magnetic field, used in soft robotics and biomedical devices.

Magnetically responsive elastomers

Magnetically responsive elastomers, also called magnetic elastomers, are composites of magnetic particles embedded in a soft polymer such as silicone, allowing remote actuation by an external magnetic field.

Magnetism

Magnetism is the physical phenomenon in which moving electric charges and the magnetic moments of particles produce magnetic fields, arising in atoms from electron motion and spin.

Magnetite

Magnetite is an iron oxide mineral, Fe₃O₄, the most strongly magnetic naturally occurring mineral and, alongside hematite, one of the two principal ores of iron, forming black octahedral crystals.

Magnetization

Magnetization, also called magnetic polarization, is the magnetic dipole moment per unit volume of a material, describing how strongly it responds to or retains a magnetic field.

Magnetization nutation

Magnetization nutation is a rapid oscillation of a magnetic moment's axis superimposed on slower precession, arising from spin inertia on picosecond time scales and first observed directly in 2020.

Magnetization transfer

Magnetization transfer (MT) is an MRI technique that generates image contrast by exchanging magnetization between free water and macromolecule-bound protons, first applied in 1989 and widely used to assess myelin integrity.

Magnetization transfer imaging

Magnetization transfer imaging is an MRI technique, introduced by Wolff and Balaban in 1989, that measures macromolecular content such as myelin and is mainly applied to multiple sclerosis.

Magnetization transfer MRI

Magnetization transfer MRI is an MRI technique that uses off-resonance radiofrequency pulses to probe invisible macromolecular protons, providing one of the main measures of myelin content in vivo.