Photoluminescence and magnetic properties of β-Ni(OH)2 nanoplates and NiO nanostructures

Single-crystalline beta-nickel hydroxide (beta-Ni(OH)(2)) nanoplates of hexagonal structure have been synthesized through hydrothermal process. The beta-Ni(OH)(2) nanoplates possess well-defined hexagonal shapes with landscape dimension of 45-140 nm and thickness of 20-50 nm. Post-thermal decomposition of the beta-Ni(OH)(2) nanoplates led to the formation of single-crystalline NiO nanostructures with landscape dimension of 25-120 nm including nanorolls, nanotroughs and nanoplates. The sizes of the central hole in NiO nanorolls and the low-lying ground in NiO nanotroughs are in the range of 10-24 nm. Two photoluminescence emission peaks appear at 390.5 nm and 467 nm in the photoluminescence spectrum of NiO nanostructures and were assigned to the T-1(1) (g) (G) -> (3)A(2) (g) and T-1(2) (g) (D) -> (3)A(2) (g) transitions of Ni2+ in oxygen octahedral sites, respectively. Temperature-dependent magnetic measurement results show that an antiferromagnetic-paramagnetic transition occur at 26.3 K in beta-Ni(OH)(2) nanoplates.