⁵⁷Fe Mossbauer effect measurements have been performed at room temperature on Y(Ba₁-ₓSrₓ)₂(Cu₀.₉₉Fe₀.₀₁)₃O[sub y] with x from 0 to 1. In all samples, four quadrupole splittings, corresponding to iron atoms in different ...

Mossbauer effect measurements at ⁵⁷Fe nuclei have been made at room temperature on Y₁₋ₓ Prₓ Ba₂ (Cu₀.₉₉Fe₀.₀₁)₃ O[sub y] with x = 0, 0.1, 0.2, 0.4, 0.5, 0.6, and 0.7. Neutron diffraction experiments show that iron atoms ...