Nuclear magnetic resonance in amorphous and crystalline cobalt base alloys

By the method of pulse NMR investigated is the structure of amorphous and crystalline cobalt base alloys, containing iron, silicon and boron. NMR measurements are carried out by the spin-echo method within 70-210 MHz frequency range at 4.2 K. Amorphous alloy spectra are characterized by wide distribution of hyperfine fields of 60Co. Spectral width approximately equals 30-40 MHz. The peak relative amplitude increases at 170 MHz with the increase of silicon content. Comparison of NMR spectra of amorphous and crystalline alloys shows, that a part of the spectrum of cobalt amorphous alloys within 100-150 MHz frequency range is connected with 56Co nuclei resonance. Some spectra within 150-210 MHz frequency range with the maximum at 165-175 MHz are bound with resonance of cobalt nuclei atoms, having neighbouring order. The existing data on NMR in amorphous cobalt base alloys show, that the atomic structure of amorphous alloys is characterized by strong effects of neighbouring atomic ordering of different type