Three-pulse spin echo signals from quadrupolar nuclei in magnetic materials

The time evolutions of the three-pulse spin echo signals from quadrupolar nuclei 63Cu and 53Cr in ferromagnetic CuCr2S4:Sb have been investigated at the temperature T=77 K. The experimental results were well explained by the developed theory of the time evolutions of the three-pulse echoes. The main assumption of this theory is the assumption that the temporal fluctuations in the electron magnetization lead to the fluctuations in the hyperfine and quadrupole interaction Hamiltonians.