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Nanocrystals 3835 3.1. Progress in Mn 2 O 3 Nanomaterials 3835 3.2. Synthesis of Mn 2 O 3 Nanocrystals 3836 3.2.1. Method 3836 3.2.2. Instrumental Analysis 3836 3.3. Grain Growth Kinetics of Mn 2 O 3 Nanocrystals 3836 3.3.1. Kinetic Analysis 3836 3.3.2. Microstructure Analysis 3838 3.4. Spectral Properties of Mn 2 O 3 Nanocrystals 3839 3.4.1. Raman Features of Different Grain Sizes 3839 3.4.2. IR Features of Different Grain Sizes 3840 3.4.3. XPS Analysis of Different Grain Sizes 3841 3.4.4. ESR Analysis of Different Grain Sizes 3843 4. Controllable Synthesis and Microstructure Evolution of Mn 3 O 4 Nanocrystals 3844 4.1. Progress in Mn 3 O 4 Nanomaterials 3844 4.2. Shape-Controlled Synthesis of Mn 3 O 4 Nanocrystals 3845 4.2.1. Synthesis Techniques 3845 4.2.2. Instrumental Analysis 3845 4.3. Microstructure Evolution of Single-Crystal Mn 3 O 4 Nanocrystals 3845 4.3.1. Mn 3 O 4 Nanoparticles 3845 4.3.2. Mn 3 O 4 Nanorods 3846 4.3.3. Mn 3 O 4 Nanofractals 3846 4.3.4. HRTEM Investigation of Mn 3 O 4 Nanocrystals 3847 4.3.5. Spectral Characteristics of Mn 3 O 4 Nanocrystals 3847 4.3.6. Formation Mechanism of Mn 3 O 4 Nanocrystals 3849 5. Summary and Outlook 3849 5.1. Summary 3849 5.2. Outlook 3850 5.3. Concluding Remarks 3850 Author Information 3850 Corresponding Author 3850 Notes 3850 Biographies 3850 Acknowledgments 3852 List of Abbreviations 3852 References 3852

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Nanometer manganic oxide (Mn2O3) has been prepared by the chemical liquid homogeneous precipitation (CLHP) method. The size dependence of phonon Raman spectra in Mn2O3 nanocrystals has been investigated. Transmission electron micrographs and X-ray powder diffraction patterns show that the average particle sizes are in the range of 9 to 50 nm. From the Raman spectra patterns of the nanometer Mn2O3 particle, we determined the broadening of the Raman peak in the lower frequency region. This phenomenon was explained by a spatial correlation model. We also found that the intensities of the main Raman peak decrease with the decrease in the grain size of Mn2O3 nanocrystals.

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Results on Al-induced crystallization of amorphous Ge (a-Ge) deposited by vacuum thermal evaporation techniques under thermal annealing in N(2) atmosphere are presented in detail. The a-Ge crystallization and fractal Ge pattern formation on the free surface of annealed Al/Ge bilayer films deposited on single-crystal Si (100) substrates were investigated by using scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM), energy dispersive X-ray spectrometry (EDS), and Raman spectra. It is found that the temperature field effects play an extremely crucial role in a-Ge crystallization and fractal Ge formation process. The open branched structure of fractal Ge clusters in Al/Ge bilayer films was effectively prepared by Al-induced crystallization when they were annealed at 400 °C for 60 min. These films with fractal Ge clusters exhibit charming noninteger dimensional nanostructures, which differ from those of conventional integer dimensional materials such as one-dimensional nanowires/nanorods, nanotubes, nanobelts/nanoribbons, two-dimensional heterojunctions, thin films, and zero-dimensional nanoparticles. The SEM image shows that a big Al grain was found located near the center of a fractal Ge cluster after the films were annealed at 400 and 500 °C for 60 min. This suggests that the grain boundaries of polycrystalline Al films are the initial nucleation sites of a-Ge. It also validates the preferred nucleation theory of a-Ge at triple-point grain boundaries of polycrystalline Al at the interface. This discovery may be explained by the metal-induced nucleation (MIN) mechanism.

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