Nuclear magnetic double resonance based on strong rf magnetic-field-induced coupling between spin systems

Abstract

The origin of the rf magnetic-field-induced coupling between spin systems is discussed. A new nuclear-double-resonance technique employing this coupling is proposed, which has particular value in measuring pure nuclear-quadrupole-resonance spectra of integer-spin nuclei by nuclear double resonance.

Proton tunnelling in KH2PO4

“…The problem can be solved by a measurement of the 170 quadrupole coupling tensor using proton-170 double resonance techniques (Slusher and Hahn, 1968;Seliger, Blinc, Mali, Osredkar and Prelesnik, 1975;Brosnan and Edmonds, 1981;Seliger, Zagar and Blinc, to be published). Here again the 1 7 0 quadrupole coupling tensor depends on the length of the 0-H bond and one can easily discriminate between a symmetric and an asymmetric H-bond.…”

Measurement of the 14N nuclear quadrupole resonance frequencies by the solid effect

“…The double resonance on the basis of magnetic field cycling and the application of the phase-modulated rf magnetic field [1] is in this case much less effective than in case of half-integer-spin nuclei. Various 1 H-14 N NQDR techniques based on magnetic field cycling [3][4][5][6][7][8][9] have been developed with the aim of increasing the sensitivity and resolution of the 14 N detection.…”

14N NQR study of nicotinamide and related compounds

“…The above spectra are not very precise and contain also the contributions of the solid effect [11] and level crossing. [12] Nevertheless, such spectra show the approximate location of the NQR frequencies, which simplifies the application of the NQDR techniques with multiple frequency sweeps and two-frequency irradiation.…”

“…[10] The double-resonance lines obtained by this technique are, in addition, often accompanied by the solid-effect lines of comparable intensity which are shifted from the NQR frequencies. [11] A much higher sensitivity is obtained in the case of 14 N using the technique based on magnetic field cycling and multiple frequency sweeps. [7] Here, the rf magnetic field is applied as a series of continuous frequency sweeps between the limits ν l and ν u ( Fig.…”