Bohr magneton - Definition

The Bohr magneton (symbol <math>\mu_B<math>) is named after the physicist Niels Bohr. It is a physical constant of magnetic moment, defined by:

<math>\mu_B = {{e \hbar} \over {2 m_e}}<math>

where:

<math>e<math> is the elementary charge,

<math>\hbar<math> is the reduced Planck's constant,

<math>m_e<math> is the electron rest mass

In the SI system of units its value is approximately:

<math>\mu_B<math> = 9.274 008 99(37) × 10^-24 J·T^-1

See also

• Physical constant