Preparation And Characterization Of CuI And Fe₃O₄ Nanomaterials

Based on the important role of application of optical and magnetic materials in practical life, the aim of this thesis involve the preparation and properties characterization of CuI and Fe₃O₄ crystals with nanosize.CuI nanocrystals with different shapes were successfully prepared. Under the control of microemulsion, complexing agents and temperature, rodlike, sheetlike and cubic nanocrystals were obtained, respectively. XRD, TEM, EIS and UV were used to characterize the phase, microstructure and properties of the products. It seems that the rod-like-structure Cu(dmg)2 as precursors can lead the product Cul growing in one direction especially to form one-dimensional materials and the reverse microemulsion system plays an important role in making products more symmetrical and uniform. Energy bands of the sample show blue shifts comparing by that of bulk materials, which is attributed to the quantum size confinement effect of the nanorods. Impedance spectra indicate that the resistance of Cul nano-particles is larger than CuI agglomerates, which may due to the larger grain boundary resistance of nano-particles.Nanosized powders of Fe₃O₄ were synthesized by precipitation method, hydrothermal and solvothermal method. Fe₃O₄ nanocrystals with different shaped including global, sheetlike and cubic nanomaterials were obtained. XRD, TEM and VSM were used to characterize the products. In this work, spherical Fe₃O₄ nanoparticles with average diameter of 50 nm were prepared by simple deposition at room temperature, hexagonal and quadrangular Fe₃O₄ nanoflakes with average diameter of 100 nm were prepared by solvothermal method at 180℃, quadrangular cubes with average diameter of 300 nm were prepared by hydrothermal method at 180℃. The saturated magnetizations and coercivities of the three samples are 88 emu/g and 175 Oe, 100 emu/g and 155 Oe, 87 emu/g and 136 Oe in sequence, which indicates that all of the samples we obtained have good magnetic properties.