Influence of Thermomechanical Synthesis Conditions on Phase Composition and Magnetic Structure of Nonequilibrium Au–Co Alloys

The paper presents the results of study of the magnetic structure of nonequilibrium gold–cobalt alloys obtained by high pressure torsion under different thermomechanical conditions in terms of temperature and strain magnitude. X-ray diffraction data analysis by Rietveld method has revealed incomplete dissolution of cobalt after 10 anvil revolutions at 300 K. In contrast, the same shear deformation at 80 K leads to complete dissolution of cobalt, accompanied by the formation of two solid solutions with different cobalt contents. The use of magnetic force microscopy has revealed that specimens subjected to mechanosynthesis at 300 K possess the stripe domain structure that is not observed in specimens after cryo-deformation. Vibrational magnetometry of the synthesized alloys has revealed a decrease in the saturation magnetization with increasing shear strain and decreasing temperature of mechanical alloying.