Gyromagnetic ratio

Is the gyromagnetic ratio (also magnetogyric ratio ) is the proportionality factor between the angular momentum ( or spin ) of a particle and its associated magnetic moment

Therefore follows:. The unit used internationally as the gyromagnetic ratio is A · s · kg -1 · s-1 or T -1.

The gyromagnetic ratio of a charged particle is the product of its ( dimensionless ) and gyromagnetic factor of his magneton, based on the reduced Planck constant:

With

  • The magneton of the particle
  • : Electrical charge
  • : Particle mass.

The gyromagnetic ratio can be determined by utilizing the Barnett effect and the Einstein-de Haas effect. In many other experiments such as ferromagnetic resonance or electron spin resonance, the value of can vary significantly - in this case one speaks of the spectroscopic splitting factor or ratio.

For pure orbital angular momentum of an electron

As stated in the article Magnetic moment, applies to the magnetic moment of the orbital angular momentum of an electron:

With

  • The charge of an electron
  • Its mass.

Hence it follows:

With

  • Bohr magneton. The g- factor for the orbital motion is therefore

For the spinning of a particle

If we consider a particle with spin, then:

The value of this constant of nature is characteristic for each particle. According to current measurement accuracy it is

  • For the free proton:
  • For the electron:

Thereby give the bracketed numbers in each case the estimated standard deviation for the mean value of which corresponds to the last two digits before the brackets.

The g- factor for spin magnetism is the free electron almost exactly - down to seven decimal places - equal to 2 analog In free proton, however, by no means applies: the magnetic moment of the proton is indeed the order after at the so-called " nuclear magneton " ( that would be the value) is but a krummzahliges multiple of this value, more precisely, the 2.79 -fold.

Ferromagnetic metals iron, cobalt and nickel have electronic g -factor very close to 2 (z example, only about 10% more or less), that is the magnetism of these systems is primarily spin magnetism but with low web portion.

Gyromagnetic ratios of nuclei

For cores, this ratio can be measured and reported. In the following table some results are listed.

Ampere Einstein–de Haas effect
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