Abstract
Using a SQUID magnetometer, changes in the nuclear magnetization of copper are observed when the nuclear spins absorb rf power at resonance. Since the detected flux change is directly proportional to the change in static magnetizationΔM, this method offers higher sensitivity at low frequencies than conventional NMR which responds todM/dt. The experimental arrangement for observingΔM at temperatures below1 K is described. The variation of signal amplitude with temperature and rf power is found to agree well with predictions from the Bloch equations. A comparison of the sensitivity of the SQUID magnetometer and conventional NMR methods shows the advantage of the new technique at low frequencies and for nuclear systems with broad lines and long spin-lattice relaxation times.
Similar content being viewed by others
References
E. C. Hirschkoff, O. G. Symko, L. L. Vant-Hull, and J. C. Wheatley,J. Low Temp. Phys. 2, 653 (1970).
J. H. Bishop, E. C. Hirschkoff, and J. C. Wheatley,J. Low Temp. Phys. 5, 607 (1971).
A. H. Silver and J. E. Zimmerman,Appl. Phys. Lett. 10, 142 (1967).
E. P. Day,Phys. Rev. Lett. 29, 540 (1972).
D. J. Meredith, G. R. Pickett, and O. G. Symko,Phys. Lett. 42A, 13 (1972).
A. J. Hildebrandt, H. Wahlquist, and D. Elleman,J. Appl. Phys. 6, 533 (1972).
U. El-Hanany and D. Zamir,Phys. Rev. 183, 809 (1969).
R. P. Giffard, R. A. Webb, and J. C. Wheatley,J. Low Temp. Phys. 6, 533 (1972).
N. Bloembergen,Nuclear Magnetic Relaxation, (Benjamin, New York, 1961), p. 65.
H. D. W. Hill and R. F. Richards,J. Sci. Instr. 1 (ser. 2), 977 (1968).
R. A. Kamper, L. O. Mullen and D. B. Sullivan, NBS Technical note 381, p. 32 (1969).
J. Schratter and D. L. Williams,Phys. Rev. B 5, 4302 (1972).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Meredith, D.J., Pickett, G.R. & Symko, O.G. Application of a SQUID magnetometer to NMR at low temperatures. J Low Temp Phys 13, 607–615 (1973). https://doi.org/10.1007/BF00656548
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00656548