Synthesis, Optical, and Magnetic Properties of Ba₂Ni₃F₁₀ Nanowires

A low-temperature hydrothermal route has been developed, and pure phase Ba₂Ni₃F₁₀ nanowires have been successfully prepared under optimized conditions. Under the 325 nm excitation, the Ba₂Ni₃F₁₀ nanowires exhibit three emission bands with peak positions locating at 360, 530, and 700 nm, respectively. Combined with the first-principles calculations, the photoluminescence property can be explained by the electron transitions between the t_2g and e_g orbitals. Clear hysteresis loops observed below the temperature of 60 K demonstrates the weak ferromagnetism in Ba₂Ni₃F₁₀ nanowires, which has been attributed to the surface strain of nanowires. Exchange bias with blocking temperature of 55 K has been observed, which originates from the magnetization pinning under the cooling field due to antiferromagnetic core/weak ferromagnetic shell structure of Ba₂Ni₃F₁₀ nanowires.