Structural and magnetic investigation of mechanically alloyed Fe80Co5(NbxZr1-x)(7)B-8 powders

Experimental results concerning the structural and soft magnetic properties of nanocrystalline Fe80Co5(NbxZr1-x)(7)B-8 (x = 0.3, 0.4 and 0.5) powders obtained by high-energy ball milling of elemental powders in argon atmosphe re are reported in this work. The initially crystalline diffraction lines c orresponding to the unmilled Fe80Co5(NbxZr1-x)(7)B-8, (x = 0.3, 0.4 and 0.5 ) powders are considerably broadened after ball milling due to the reductio n of the crystal sizes and increase of internal strains. The average crysta llite sizes, measured by X-ray diffractometry using the Warren-Averbach met hod, 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 s ample magnetometry, of Fe80Co5(NbxZr1-x)(7)B-8, (x = 0.3, 0.4 and 0.5) mech anically alloyed powders is obtained after the thermal treatment of the sam ples at temperatures between 100 degreesC and 400 degreesC, for 1 h, due to strain relaxation which was measured by X-ray diffractometry. (C) 2001 Els evier Science B.V. All rights reserved.