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59Co nuclear magnetic resonance (NMR) measurements have been undertaken to determine the local atomic environment of Co in Co/V multilayers, previously studied by magnetometry. These NMR measurements provide confirmation, on a local atomic scale, of the results deduced from the earlier magnetization study. Co/V multilayers show considerable interfacial mixing with a magnetically dead, vanadium rich layer penetrating approximately 2 A into an adjoining Co layer. The presence of this dead layer has the effect of modifying the hyperfine field experienced by the Co nuclei at a distance of several atomic planes from the interface.

59Co NMR and magnetotransport measurements have been undertaken on a series of molecular beam epitaxy grown Co 22 A/Cu 32 A(111) multilayers as a function of the number of repeat units in the multilayer stack. Examining the positions of the bulk [Co surrounded by 12 Co nearest neighbors (NN)] and ideal planar interface (Co surrounded by 9×Co and 3×Cu NN) lines showed that increasing the number of repeat units leads to greater strain in the Co layers indicating better epitaxial registry. Interfacial mixing was studied by examining the ratio of the relative signal strength of the bulk and ideal planar interface lines compared to the signal outside these regions. The relative intensity of the NMR signal outside the bulk and ideal interface lines clearly reduces as the number of repeat units is increased. This demonstrates that in these samples the interfacial quality improves as the number of repeat units is increased. Magnetotransport measurements show that the improvement in structural quality could be cor...

59Co nuclear magnetic resonance (NMR) spectra of small Co particles in a SiO2 matrix have been measured. In zero field, strong signals were obtained in the frequency range of 210–250 MHz. The 59Co NMR frequency in fcc multi (single) domain particles is 217.4 (223) MHz. Possible contributions to the Co hyperfine field and changes to the Co magnetic moment in nanoclusters are discussed. An enhanced magnetic moment could be responsible for an increase in the hyperfine field leading to the observed NMR line at ∼243 MHz. Measurements of the transverse relaxation time (T2) as a function of temperature and field are reported.

59Co and 55Mn NMR measurements have been made on a range of CoMn materials: dilute powder alloy, thin‐film alloys, and multilayers. Our results suggest that in dilute alloys isolated atoms of Mn couple both ferro and antiferromagnetically to the Co host, with the latter producing a reduction in the magnitude of the Co hyperfine field of 17%. This reduction of hyperfine field appears similar for both the fcc and hcp phases of Co. NMR on Co/Mn sputtered multilayers shows large changes in the hyperfine field distribution between a film with Mn layers of 10 A and Mn layers of 30 A.

The distribution of effective field at the 59Co nucleus in alloys of composition CocNi1−c has been studied for c[similar or greater-than]0.93 using an automatic swept frequency spin‐echo NMR spectrometer at 4.2°K. Three satellite lines were observed displaced approximately 7.5 MHz, 15 MHz, and 22 MHz below the main line at 217.4 MHz. The intensities of the satellite lines relative to the main line are in good agreement with the probabilities of configurations with one, two, and three nickela toms respectively in the near‐neighbor shell. A further partially resolved satellite 2 MHz below the main line was also observed and attributed to nuclei with one nickel atom in the next‐nearest neighbor shell and none in the first‐neighbor shell. From these measurements it is concluded that the magnetic disturbance produced by a nickel atom in the cobalt lattice is well localized, in agreement with the neutron‐diffraction measurements.