The magnetic properties of several iron-rich amorphous alloys of the form a-${\mathrm{Fe}}_{\mathit{x}}$${\mathit{T}}_{100\mathrm{-}\mathit{x}}$ (T=Zr,Hf,Sc; x∼90) have been studied down to 5 K using magnetization measurements and Mössbauer spectroscopy, both with and without an external magnetic field. Two magnetic transitions are observed: first to a collinear magnetic state at ${\mathit{T}}_{\mathit{c}}$, then noncollinearity develops at ${\mathit{T}}_{\mathit{x}\mathit{y}}$. Analysis of the composition and temperature dependences of the magnetic ordering allows us to rule out cluster-based models of the behavior. All of our results can be explained in terms of a homogeneous freezing of transverse spin components at ${\mathit{T}}_{\mathit{x}\mathit{y}}$ leading to a state in which ferromagnetic and spin-glass order coexist. Quantitative agreement with Monte Carlo simulations of a bond-frustrated Heisenberg system is observed.

• Received 16 January 1995

DOI:https://doi.org/10.1103/PhysRevB.51.15885