Structural and magnetic investigation of mechanically alloyed Fe80Co5(Nb Zr1−)7B8 powders

Experimental results concerning the structural and soft magnetic properties of nanocrystalline Fe 80 Co 5 (Nb x Zr 1-x ) 7 B 8 , (x = 0.3, 0.4 and 0.5) powders obtained by high-energy ball milling of elemental powders in argon atmosphere are reported in this work. The initially crystalline diffraction lines corresponding to the unmilled Fe 80 Co 5 (Nb x Zr 1 ) 7 B 8 , (x = 0.3, 0.4 and 0.5) powders are considerably broadened after ball milling due to the reduction of the crystal sizes and increase of internal strains. The average crystallite sizes, measured by X-ray diffractometry using the Warren-Averbach method, in the final samples obtained after 250 h ball milling were between 7.5 and 11.4 nm. A change in the magnetic properties, measured by vibrating sample magnetometry, of Fe 80 Co 5 (Nb x Zr 1 ) 7 B 8 , (x = 0.3, 0.4 and 0.5) mechanically alloyed powders is obtained after the thermal treatment of the samples at temperatures between 100°C and 400°C, for 1 h, due to strain relaxation which was measured by X-ray diffractometry.