Mn-doped
CuInSe 2 compounds (CuIn 1Γx Mn x Se 2 , x ΒΌ 0.0125-0.20 and Cu 1Γy In 1Γy Mn 2y Se 2 , 2y ΒΌ 0.0125-0.60) were synthesized by high-temperature solid-state reactions. Single phase materials with chalcopyrite structure persist up to 0.10 and 0.20 doping for CuIn 1Γx Mn x Se 2 and Cu 1Γy In 1Γy Mn 2y Se 2 , respectively. The chalcopyrite and sphalerite phases co-exist in the Cu 1Γy In 1Γy Mn 2y Se 2 system for 2y ΒΌ 0.25-0.50. Attempts to introduce greater manganese content, x ΒΌ 0.15-0.20 for CuIn 1Γx Mn x Se 2 and 2y ΒΌ 0.60 for Cu 1Γy In 1Γy Mn 2y Se 2 , result in partial phase segregation. For the single-phase samples, the lattice parameters of both systems increase linearly with manganese concentration and thus follow Vegard's law. The temperature of the chalcopyrite-sphalerite phase transition is decreased by manganese substitution for all single-phase samples. The bandgap of the materials remains around 0.9 eV. Additionally, the Mn-doped CuInSe 2 compounds display paramagnetic behavior, whereas pure CuInSe 2 is diamagnetic at 5-300 K. All the CuIn 1Γx Mn x Se 2 and Cu 1Γy In 1Γy Mn 2y Se 2 compounds with chalcopyrite structure show antiferromagnetic coupling and measured effective magnetic moments up to 5.8 m B /Mn.