  The atomic distribution in amorphous FeZr alloys is found to be close to
random, nevertheless, the composition can not be viewed as being homogenous at
the nm-scale. The spatial variation of the local composition is identified as
the root of the unusual magnetic properties in amorphous Fe$_{1-x}$Zr$_{x}$
alloys. The findings are discussed and generalised with respect to the physical
properties of amorphous and crystalline materials.
