2-DIMENSIONAL FOURIER-TRANSFORM OF ELECTRON SPIN-ECHO ENVELOPE MODULATION - ALTERNATIVE FOR ENDOR

The nuclear modulation effect in electron spin-echo is experimentally studied by means of Fourier analysis. The Fourier spectrum shows, besides a good resolution, a good response for hyperfine frequencies in an extremely low frequency range (30 kHz to 1 MHz). The Fourier spectrum may suffer from blind spots, however. It is demonstrated that these can be circumvented by extending the measurement of the modulation data to two time parameters. These data may be Fourier transformed to a two-dimensional spectrum with some interesting properties. One of these facilitates the assignments of peaks in the spectrum. Experimental results of the 14N modulation of the electron spin-echo envelope of Bi2Mg3(NO3)12·24H 2O:Gd3+ are given. © 1979 American Chemical Society.