Effect of Gd and Fe doping on magnetic properties of Al87Y5Ni8 amorphous alloy

Magnetic properties and crystallization behavior of Al–Co–Ce(Dy) amorphous ribbons

“…At the same time Ce atoms in glassy Al 87 Fe 9 Ce 4 show large valence instability, yielding an effective moment of 1.37 µ B at room temperature to ~ 0.25 µ B at 5 K. The similar results were obtained in [12]. The authors in [14] point attention on the fact that the value of the effective magnetic moment per Ni atoms (0,3 µ B ) in amorphous aluminum matrix Al 87 Y 5 Ni 8 is significantly lower than its ionic value 3.2 µ B as well as its value of crystalline Ni -0.6 µ B . According to their results, Al-Y-Gd-Ni-Fe amorphous alloys behave as a typical paramagnetic body, but on the other hand the isotherms M(H) measured at 2K show a saturation effect indicating a possible superparamagnetic clustering.…”

“…This obviously means that Gd atoms introduce some antiferromagnetic coupling within the cluster. A partial substitution of Ni atoms by Fe essentially does not change magnetic structure of the examined alloys [14]. The supposition made in this work is that gadolinium atoms exist in the ion form.…”

Numerical analysis of superparamagnetic clusters distribution

“…The first example is a family of Al-RE-TM (RE, rare earth; TM, transition metal [14,15] amorphous alloys. shows isotherms M(H) obtained for the Mn(Si)-1 and Mn(Si)-2 samples measured at temperature of 300 K (all diamagnetic and paramagnetic components were subtracted).…”

“…The first example is a family of Al-RE-TM (RE, rare earth; TM, transition metal [14,15] amorphous alloys. procedure (Fig.…”

“…6) reveals that the cluster distribution consists of two components with maxima at 1.8 and 16.5 m B . A value of magnetic moment per Ni atom in amorphous alumina (equals to 0.3 m B[15]) was determined from saturation magnetization.The component with low magnetic moment can be attributed to small paramagnetic Ni clusters and the second one to larger superparamagnetic clusters consisting of about 50 Ni atoms. In the case of the Al 87 Y 4 Gd 1 Ni 8 amorphous alloys the cluster picture is more complex, as shown inFig.…”