In atomic physics, the Bohr magneton (symbol μ_B) is a physical constant of magnetic moment of electrons. It was discovered in 1913 by Romanian physicist Ştefan Procopiu^[1] and rediscovered independently two years later by Danish physicist Niels Bohr. It is sometimes called the Bohr–Procopiu magneton.

The value of Bohr magneton

system of units	value	unit
SI[2]	9.27400915(23)×10−24	J·T−1
CGS[3]	9.27400915(23)×10−21	Erg·Oe−1
eV	5.7883817555(79)×10−5	eV·T−1
atomic units	1⁄2	none

The Bohr magneton is defined in SI units by

and in Gaussian centimeter-gram-second units by

where

e is the elementary charge,

ħ is the reduced Planck constant,

m_e is the electron rest mass and

c is the speed of light.

The Bohr magneton is the natural unit for expressing an electron magnetic dipole moment. An electron has an intrinsic magnetic dipole moment of approximately one Bohr magneton.^[4]

[edit] References

[edit] See also

• Nuclear magneton
• Physical constant
• Anomalous magnetic moment
• Weiss magneton