ROTATIONAL SPIN-GLASS PROPERTIES OF AMORPHOUS (FE1-XMNX)75P16B6AL3

For the x = 0.235 alloy, the bifurcation of the magnetization (M) versus temperature curves for zero-field cooling and field cooling indicates a spin-glass freezing point (T(g)) near 60 K. Above T(g), the alloy is ferromagneticlike (with T(c) almost-equal-to 300 K) but its behavior at low fields (< 100 Oe) shows that the bulk spontaneous M is zero, which is consistent with the existence of microdomains with randomly oriented spontaneous moments. From rotational measurements of M as a vector in a fixed field (H) at 4.2 K, the anisotropy field (H(K)) produced by field cooling to saturation is found to turn rigidly with the sample but only for H < 100 Oe. At higher H, H(K) rotates up to some angle relative to H, where it remains as the sample continues to turn, thus exhibiting a frictional rotation relative to the sample. The magnitude of the rotating H(K) at 4.2 K is determined to be 310 Oe. Comparisons are made with the results of similar magnetization-vector measurements on other spin-glass systems.