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Lead iodide nanoparticles are synthesized in reverse micelle solution of AOT/H2O/n-heptane. Optical absorption spectra and TEM analysis indicated the formation of crystalline particles with an average radius of 1.5 nm, which is less than the Bohr radius of the exciton (1.9 nm) in bulk PbI2. Using theoretical models and optical spectra of quantum confined PbI2 nanoparticles, a radius of 1.5 nm and a thickness of 1.7 nm was calculated, which are in full agreement with the TEM results. Particles were isolated from the dispersed medium and were analysed by powder XRD and Raman spectroscopy, indicating the formation of a predominantly 2H-PbI2 polytype. This work presents the first case of fully isolated, fully characterized solid nanoparticles of PbI2. It also presents XRD and Raman spectrum for the first time for PbI2 nanoparticles of intermediate quantum confinement. [ABSTRACT FROM AUTHOR]

According to ultraviolet (UV)-vis absorption spectra recorded in the DNA metallization process, DNA-templated Co/Cu binary nanoparticle chains are fabricated by incubating genome DNA of paralichthys olivaceus muscle in CoCl2 and CuCl2 mixture solution for 20 hours and reducing the complex for 2 hours. Transmission electron microscopy observation indicates that Co and Cu nanoparticles with 20 nm in diameter were randomly dispersed on the DNA template. The superconducting quantum interference device (SQUID) measurements display that the magnetic interaction between cobalt particles is greatly decreased by the copper particle. With increasing copper content, the coercivity of the systems enhance from 9 Oe to 100 Oe (1 Oe = 79.5775 A/m). [ABSTRACT FROM AUTHOR]