Alloys with Compositions Co-25.5wt/o Sm-Sw/o Cu-15 w/o Fe-3w/o Zr and Co-Sra-Cu-Fe-1.5 w/o Zr have ibeen step aged to produce magnets with coercive force (iHc) in the range of 10-25k0e, much higher than those reported so far in the litera ture for the Zr alloys. The high coercive force magnet s are typically aged at 800-850°C for 10-30 hours following the solution treatment at 1150°C. Subsequently, these are step aged to produce materials with high coercivity. The microstructure in all these alloys has a 2 phase cellular morphology with 2:17 phase surrounded by a 1:5 boundary phase. The long aging treatments at 800-850°C lead to coarsening of the two phase structure. The subsequent stepaging does not change the morphology, but only changes the chemical composition of th:* two phases.Best properties are obtained in materials with a cohe rent microstructure of optimum boundary phase thickness and optimum chemical composition. The highest values of iHc ob tained so far are % 26k0e and a. 16 kOe for the 3% Zr and 1.52 Zr alloys respectively. The (best hard magnetic properties of (B?0 max = 33 MGOe and iHc = 13k0e are for a 25% Sm-20%Fe-4 Cu-2%Zr alloy.
We propose some improvements in the form of the eikonal wavefunction and a more rigorous evaluation of the integral for the DWBA amplitude for electron-nucleus scattering as given by Yennie. Our calculations are found to be in closer agreement with the phase-shift results than those of Yennie er al (for e'-Au scattering) and Rosenfelder (for e--Pb scattering based on the eikonal approximation of the T matrix). The improved eikonal method is applied to the study of the isotopic effect in e--Ti scattering. The effect of the addition of a small oscillatory part to the smoothly varying nuclear charge distribution for e--32S scattering at high momentum transfer is also investigated with the help of our eikonal method.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.