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 t2g and eg 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.
Keywords: exchange bias; fluorides; multiferroic; nanowire; photoluminescence.