Synthesis and structure–property relations in xCuO–(1 − x)Bi2O3 (0.5 ⩽ x ⩽ 0.9) (C1–C5: x = 0.5, 0.6, 0.7, 0.8, 0.9) glasses

Synthesis of the xCuO–(1 − x)Bi2O3 (0.5 ⩽ x ⩽ 0.9) (C1–C5: x = 0.5, 0.6, 0.7, 0.8, 0.9) glasses was done via nitrate–citrate gel route. Glassy phase is ascertained by XRD studies. Magnetic susceptibility results in the range 4.2–400 K show weak paramagnetic nature with exchange integrals ∼0.024–0.13 eV in the glasses. The electron paramagnetic resonance (EPR) in the range 4.2–363 K shows g ≈ 2.0 and the trend of the g-matrix elements g|| > g⊥ > ge for the glasses C1–C5 at 4.2 K are due to the Cu2+ (3d9) paramagnetic site in the glasses which is in a tetragonally elongated octahedron [O1/2–CuO4/2–O1/2] having D4h symmetry. IR spectroscopic results show the presence of octahedron [BiO6/2]3− and [CuO6/2]4− units and pyramidal [BiO2/2O]− unit in the glasses.