Monodisperse wurtzite CuIn(x)Ga(1-x)S(2) nanocrystals have been synthesized over the entire composition range using a facile solution-based method. Depending on the chemical composition and synthesis conditions, the morphology of the nanocrystals can be controlled in the form of bullet-like, rod-like, and tadpole-like shapes. The band gap of the nanocrystals increases linearly with increasing Ga concentration, with band gap values for the end members being close to those observed in the bulk. Colloidal suspensions of the nanocrystals are attractive for use as inks for low-cost fabrication of thin film solar cells by spin or spray coating.

Cu(2)FeSnS(4) (CFTS) nanocrystals with tunable crystal phase have been synthesized using a solution-based method. As-synthesized CFTS nanocrystals in the shape of oblate spheroid and triangular plate with band gaps of 1.54 ± 0.04 and 1.46 ± 0.03 eV, respectively, appear attractive as a low-cost substitute for thin film solar cells.

Monodisperse CuInS(2) nanocrystals are produced by injecting mixed metal-oleate precursors into hot organic solvents containing the dissolved sulphur sources. A better understanding of the formation mechanism of CuInS(2) has enabled us to tailor anisotropic shapes in the form of triangular-pyramid, circular cone, and bullet-like rods with tunable crystal phases by varying the synthetic conditions.

Novel shape- and structural-controlled superparamagnetic nanostructures composed of self-supported spherical and rod-like CoFe(2)O(4) colloidal nanocrystals have been prepared by thermolysis of a stoichiometric Co(2+)Fe(2)(3+)-oleate complex in organic solution with periodic injection of hexane for controlling the nucleation, assembly, and growth of the nuclei.

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Nanocrystals and nanoclusters of the room-temperature magnetic spinel CuCr(2)S(4) have been synthesized using a facile solution-based method. The synthesis involves hot injection of an excess of 1-dodecanethiol (1-DDT) into a boiling coordinating solvent containing CuCl(2) and CrCl(3)·6H(2)O. Using octadecylamine (ODA) as a solvent yields cube-shaped nanocrystals with an average size of 20 ± 2 nm, while with oleylamine (OLA), nanoclusters with an average size of 31 ± 2.5 nm are obtained. In both cases, powder X-ray diffraction patterns confirmed the formation of the pure spinel phase without any impurities. While the synthesized powders are superparamagnetic near room temperature, they exhibit ferromagnetic behavior at lower temperatures, with magnetization (M(S)) values of 30 emu/g (1.63 μ(B)/f.u.) and 33 emu/g (1.79 μ(B)/f.u.) for the ODA- and OLA-capped nanocrystals and nanoclusters, respectively, at 5 K.

Nanocrystals (15−30 nm) of the magnetic chalcospinel CuCr2Se4 have been synthesized using a facile solution-based method with good size control. They have close to cubic morphology with a narrow size distribution and exhibit superparamagnetic behavior at room temperature.

Magnetoelectric heterostructures are being actively investigated for utilization in next generation microwave devices such as tunable filters and phase shifters. For efficient microwave absorption and magnetoelectric coupling, relatively thick (>1 mm) epitaxial spinel ferrite films with smooth topographies are required for the magnetic/ferroelectric heterostructures. Towards this goal, direct liquid injection (DLI)-CVD has been utilized for epitaxial growth of nickel ferrite (NiFe 2 O 4 ) films on MgAl 2 O 4 (100) and MgO (100) substrates with high deposition rates. Anhydrous Ni(acac) 2 and Fe(acac) 3 (acac ¼ acetylacetonate) are used as precursor sources dissolved in N,N-dimethyl formamide for the DLI vaporizer system. The influence of deposition temperature on the film properties has been investigated using optimized process conditions for flow of the injected precursors and oxygen. Epitaxial nickel ferrite films of stoichiometric composition are obtained in the temperature range 500-800 8C on both substrates with growth rates in the range 0.6-1.1 mm h À1. Because of changes in the surface diffusion behavior, the film morphology is found to be dependent on the deposition temperature with atomically smooth films being obtained for deposition in the temperature range 600-700 8C. Magnetic measurements reveal an increase in the saturation magnetization for the films with increasing growth temperature, which correlates well with the trend for improved epitaxial growth as indicated by X-ray and Raman spectroscopy measurements. Nickel ferrite films deposited on MgAl 2 O 4 (100) at 800 8C exhibit saturation magnetization very close to the bulk value of 300 emu cm À3.