Particles Of Cu Research Articles

Study of Precipitate Particles in Cu–Co Employing Ferromagnetic Resonance

The dependence of the ferromagnetic resonance upon specimen anisotropies (shape and magnetocrystalline) is well known. Observations of the ferromagnetic resonance absorption of submicroscopic particles may be interpreted to yield useful information about these anisotropies. The alloy 2% Co–Cu heat treated to precipitate cobalt containing about ten percent copper from the nonmagnetic solid solution has been studied using ferromagnetic resonance techniques. In the early stages of growth the precipitate particles are shown to be essentially spherical in shape. Further growth of the precipitate particles (by subsequent heat treatment) is accompanied by aspherical shape changes which modify the resonance spectra. The magnetocrystalline anisotropy of the cobalt precipitate in single crystals of this alloy has been determined. This anisotropy is cubic with K1/Ms=−665 oe at room temperature. The cobalt-rich precipitate retains its cubic crystal structure to at least 4.2°K, apparently stabilized by the copper matrix.

Characteristic X-Rays Excited by Beta-Particles

Characteristic x-rays have been shown to be associated with a $\ensuremath{\beta}$-particle source. The x-rays excited in atoms outside the $\ensuremath{\beta}$-emitting atom were detected by absorption measurements and photographically, with a curved crystal spectrograph. Characteristic Cu x-rays associated with the decay of 12.8-hour ${\mathrm{Cu}}^{64}$ are attributed to the strong beta-activity of the source. Photographs of characteristic x-rays excited by ${\mathrm{P}}^{32}$ $\ensuremath{\beta}$-particles in Cu, Zr, Rh, and Ag were obtained. The characteristic x-rays and general x-radiation excited by ${\mathrm{P}}^{32}$ $\ensuremath{\beta}$-particles in Al, Cu, Ag, Sn, and Pb were studied by absorption of the radiation in Al, Cu, and Pb.