Irzooqi, Wisam Shareef (2026) A STUDY OF THE OPTICAL PROPERTIES AND ENERGY GAP TUNING THROUGH NICKEL DOPING IN Z-SCAN AND DIFFUSE REFLECTION TECHNIQUES FOR LA₀.₅SR₁.₅CO₂₋ₓNIₓO₂ COMPOSITE PARTICLES. International Journal Multidisciplinary (IJMI), 3 (4). ISSN 3031-9870