Letter | Published:

Nuclear Magnetic Resonance and Spin Lattice Equilibrium

Nature volume 158, pages 669670 (09 November 1946) | Download Citation



BY measuring the absorption of radio-frequency energy by a substance in a magnetic field due to nuclear magnetic resonance1,2, an estimate can be made of the order of magnitude of the time required for the establishment of thermal equilibrium between the spin system and the lattice. The absorption coefficient is proportional to the difference between the population of the magnetic energy states. The effect of the radio-frequency field is to tend to equalize the population of the states, so that in a strong radio-frequency field the absorption coefficient is less than in a weak field. This tendency to equalize the population of the states is opposed by the effect of the spin-lattice coupling, which tends to restore thermal equilibrium with the lattice. By finding the magnitude of radio-frequency field required to produce an appreciable reduction in the absorption coefficient, the relaxation time for transfer of energy from the spin system to the lattice can be calculated.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    , Physica, 3, 995 (1936).

  2. 2.

    , and , Phys. Rev., 69, 37 (1946).

Download references

Author information


  1. Clarendon Laboratory, Oxford. Oct. 14.

    • B. V. ROLLIN


  1. Search for B. V. ROLLIN in:

About this article

Publication history




Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.