The microstructure and interaction studies were performed for the Fe86Zr7Cu1B6 alloy in the amorphous and nanocrystalline state. It has been found that in the nanocrystalline samples containing more than 0.08 volume fraction of the crystalline alpha -Fe phase, the amorphous matrix is magnetically heterogeneous. It leads to the distribution of the Curie temperatures of this phase. The samples containing about 0.05 of alpha -Fe phase exhibit superparamagnetic behaviour above the Curie temperature of the amorphous matrix. The iron atoms situated in the interface close to the grain surface are strongly bound with those grains.