Effect of heat treatment in air and a chemically active environment on the magnetic properties of cobalt-based soft magnetic amorphous alloys

Nonuniformity of Magnetic Characteristics of a Cobalt-Based Amorphous Alloy in the As-Quenched State

“…The earlier studies showed that the surface of the stud-ied ribbon reacts with acetone [13]. The catalytic oxidation and hydrogenation of acetone [14,15] cause a decrease in the concentrations of hydrogen and oxygen atoms introduced into the ribbon surface in the course of its reaction with water or water vapor [16,17]. In this case, predominantly flat compressive stresses are induced, which, in the case of the state with the negative magnetostriction constant, favor the magnetization to the ribbon plane; in this case, the volume of domains with the orthogonal magnetization component decreases.…”

Interaction of the Ribbon Surface with Acetone and Magnetic Characteristics of the Soft Magnetic Co-Based Amorphous Alloy

“…The relative error of determination of the magnetization distribution did not exceed 5%. The sign of magnetostriction constant was determined using the water treatment (WT) of the ribbon surface at room temperature for 15 min without visible surface oxidation [3,8,9,14]. The acetone treatment (AT) was performed at room temperature by immersion of the ribbon in acetone.…”

“…Studies performed in [3] showed that the effect of treatment of the surface of a Co-Ni-Fe-Cr-Mn-Si-B amorphous alloy ribbon with acetone is opposite to that of water. As a result of chemical reactions occurring upon treatment of the ribbon surface with water, the surface oxidation and hydrogenation occur [4][5][6][7][8][9][10][11]. Hydrogen and oxygen atoms introduced into the ribbon surface induce predominantly flat anisotropic tensile stresses which, in accordance with the sign of magnetostriction constant (λ s ), differently affect the magnetization distribution.…”

“…Hydrogen and oxygen atoms introduced into the ribbon surface induce predominantly flat anisotropic tensile stresses which, in accordance with the sign of magnetostriction constant (λ s ), differently affect the magnetization distribution. For the state with λ s > 0, such stresses favor the decrease in the sharpness of in-plane magnetic texture and volume of domains with the orthogonal magnetization component (V orth ); for the state with λ s < 0, they favor the increase of V orth and magnetic texture sharpness [8][9][10]. In turn, in the case of a ribbon state with λ s > 0, the acetone treatment of the ribbon surface leads to the increase in the sharpness of in-plane magnetic texture and volume of domains with the orthogonal magnetization component; in the case λ s < 0, the acetone treatment leads to the decrease of V orth and magnetic texture sharpness.…”