The electroreduction of Co͑II͒ and Co͑II͒ + Sm͑III͒ in urea-acetamide-NaBr-MCl x melts were investigated by cyclic volatmmetry and chronoamperometry. The reduction of Co͑II͒ is an irreversible process. Sm͑III͒ cannot be reduced alone, but Sm-Co can be codeposited by induced deposition. The mechanism may involve a polynuclear complex containing Co͑II͒ and Sm͑III͒. An amorphous Sm-Co film comprised of nanoagglomerates has been synthesized. SEM shows that most of the agglomerates fall within a size range of 20-35 nm with a few agglomerates in the 50-90 nm range. The Sm content in the films varies from 7.9 to 79.16 wt % with the applied potential and the molar ratio of Sm͑III͒/Co͑II͒ in melt. The film could be crystallized by heattreatment at 900°C. Large crystal grains appeared after heat-treatment and their phase was confirmed as Sm 2 Co 17 . In addition, crystalline nanoparticles with the size of 10 nm were found on these large crystal grains. The magnetic properties of the Sm-Co films were determined using hysteresis loops, the coercive field H c of Sm ͑79.16 wt %͒-Co amorphous film is 2300 Oe at 5 K; and the remanent magnetization M R and the saturation magnetization M S are 0.536 and 1.429 emu g −1 , respectively.Rare earth ͑RE͒-transition metal ͑TM͒ alloys have excellent magnetic, optical, and electric properties and have been used to fabricate functional materials. Sm-Co alloys are widely used in permanent magnet applications because of their high-performance intrinsic magnetic properties such as very high Curie temperatures, high anisotropy fields, and relatively high saturation magnetizations. SmCo 5 alloy with the anisotropy larger than 10 8 erg cm −3 is expected to be a potential material for high-density recording media. 1 Permanent magnet materials based on Sm 2 Co 17 compound are the best candidates among all known materials for high-temperature applications. 2 Since the 1990s great progress has been made in the field of magnetic materials through the development of amorphous and nanocrystalline magnetic alloys, for example, the Finemet alloy and Nanoperm alloy which have proven to be excellent soft magnetic materials. 3,4 The amorphous RE-TM alloys, which are generally ferrimagnetic, have been intensively studied because of their potential practical applications. They can be used as magneto-optic recording media 5 because the crystallographic structure of amorphous alloys consists of a random array of atoms with very short-range correlations, leading to randomly distributed local anisotropy directions. 6 An amorphous phase may be used as a precursor to prepare a nanocrystalline structure upon crystallization. 7,8 When a certain amount of nanocrystalline phase is grown within the amorphous phase by annealing, the nanocomposite exhibits some peculiar characteristics which interest both materials scientists and engineers. 9,10 For instance, the exchange-spring magnet is prepared by the novel nanoassembly of known magnetic materials to create a composite with new and improved properties. They are based on...

Nanowires have received immense research attention in recent years due to their novel properties and potential applications in a number of different fields. [1,2] The nanometer size and low dimension of the thermoelectric material make it possible to markedly elevate the thermoelectric conversion efficiency. Semiconductor nanowires [3][4][5][6] and metal nanowires [7] offer fundamental scientific opportunities for investigating the influence of size and shape with respect to optical, electronic, and mechanical properties. For example, metal nanowires can be used as the functional components and interconnects in electronic devices, magnetic devices, and nanosensors. [8][9][10][11] As a semiconductor energy converter, Zn 4 Sb 3 is one of the most promising materials. Both theoretical calculations and experimental results show that the thermoelectric figure of merit (ZT) values of some nanometersized thermoelectric materials are several times higher than those of the bulk materials.[12]To date, nanowires have been successfully prepared through methods such as template-assisted procedures, [13][14][15] vaporphase transport processes, catalyst-assisted growth, and chemical vapor deposition (CVD). [16][17][18] Thermal evaporation is also becoming an increasingly attractive method for the synthesis of nanostructures. Various forms of ZnO, SiC, SnO 2 , In 2 O 3 , MgO, CuO, CuS, and Si nanostructures have been synthesized, including nanoparticles, nanowires, and nanobelts. [19][20][21][22][23] In this work the nanowires have been grown using heat treatment. This method is different from the typical thermalevaporation method: 1) nanoparticles of Zn-Sb, obtained using electrodeposition, were used as the precursor, while thermal evaporation uses bulk materials or powders as the source materials; 2) the system pressure was 1 atm (1 atm = 101 325 Pa), while, for thermal-evaporation methods, the system has to be kept at a low pressure; 3) the nanowires were grown at the surface of the Zn-Sb film. In the thermal-evaporation method, the nanowires were grown on another substrate which had a low temperature.Several mechanisms have been proposed to explain the growth of nanowires, including vapor-liquid-solid (VLS), [3,24] vapor-solid (VS), [25] solution-liquid-solid (SLS), [26] oxide-assisted growth (OAG), [27] and screw dislocation [28] models.However, none of these mechanisms seemed suitable to explain the growth of Zn-Sb nanowires produced in this work.No additional metals were employed as the catalyst in our heat-treatment process; the scanning electron microscopy (SEM) image shows that no droplets (catalyst heads) were found at the tips of the nanowires. On the contrary most of the nanowires had big roots, indicating that growth occurs from the point of attachment to the substrate. Therefore, the catalyst-induced VLS and SLS mechanisms may be ruled out. A low-temperature substrate was not used in our experiment, so the VS mechanism may not work. The heat treatment was carried out in an atmosphere of high-purity Ar and under th...