Like refrigerator magnets, chromium triiodide is a ferromagnet, a material that generates a permanent magnetic field owing to
the aligned spins of its electrons.
The aligned spins of electrons left a distinct sign when a beam of polarized light was reflected off the material's surface in ferromagnetic materials.
Not exact matches
Cooling this to a few degrees above absolute zero and applying a magnetic field
aligned the
spins of one phosphorus
electron per atom.
Choose some direction along which to
align the magnets — say, the z - axis — and the
spin of any
electron will only ever be found to be up or down; no
electron will ever be measured as three - quarters «up» along that direction.
Magnets are a good example
of this: the
electrons in magnets
align themselves in a preferred direction
of spin inside the material, and it is this that produces the magnetic field.
A few years ago, researchers from the University
of Cambridge showed that it was possible to create
electron pairs in which the
spins are
aligned: up - up or down - down.
And that if you heat a magnet up enough, then you have no magnet at all: High temperatures randomly jumble all the bits
of magnetic material (ultimately orientations
of spinning electrons) that had
aligned themselves along the north - to - south - pole axis.
Now, the same researchers have found a set
of materials which encourage the pairing
of spin -
aligned electrons, so that a
spin current flows more effectively in the superconducting state than in the non-superconducting (normal) state.
In antiferromagnetic materials, the
spins of electrons align in a regular pattern pointing in opposite directions to their neighbours.
But the
electrons in antiferromagnetic materials — like chromium — tend to
align so that their
spin is the opposite
of their neighbors.
Stacking up two «atomic sandwiches» yields coupled excited charge states across the planar interface with the magnetic direction or «
spin state» becoming
aligned for a large population
of electrons.
To make real use
of the
electron spin, it has to be manipulated precisely: it has to be
aligned, transmitted and detected.
In some materials,
electron spins spontaneously
align their direction, leading to the phenomenon
of ferromagnetism which is well known e.g. in iron.
This alleviates the quantum traffic jam so that, when the material is cooled to a certain temperature, oppositely
aligned electrons (magnetic partners where the «
spin»
of one
electron points up and the adjacent one points down) form pairs and then become free to zip through the material unimpeded - a superconductor.
The strength
of a magnet is a result
of the
spin of unpaired
electrons and how the
spins of different
electrons are
aligned with one another.
When a molecule or compound with an unpaired
electron is placed in a strong magnetic field, the
spin of the unpaired
electron can
align in two
When a molecule or compound with an unpaired
electron is placed in a strong magnetic field, the
spin of the unpaired
electron can
align in two Another dating method using
electron spin resonance (ESR)-- also known as
electron paramagnetic resonance (EPR)-- is based on the measurement
of
When a molecule or compound with an unpaired
electron is placed in a strong magnetic field, the
spin of the unpaired
electron can
align in two Singlet Oxygen: Generation and Properties Leonard I. Grossweiner Wenske Laser Center, Advocate / Ravenswood Hospital Medical Center 4550 N. Winchester Avenue