Group I−III−VI ternary chalcogenides have attracted extensive attention as important functional semiconductors. Among them, Cu−In−S compounds have seen strong research interest due to their potential applications in high-efficiency solar cells. However, the controllable synthesis of Cu−In−S nanostructures with different phases is always difficult. In this research, zincblende CuInS 2 , wurtzite CuInS 2 , and spinel CuIn 5 S 8 could be selectively synthesized using spinel In 3−x S 4 as the precursor by a simple solvothermal method. X-ray powder diffraction was used to determine the phase and crystal structure, and transmission electron microscopy was employed to characterize the morphologies of the as-prepared samples. Experiments showed that the acidity−basicity of the reaction system and the coordination and reducibility of the capping ligands were crucial to the final phases of the products. The UV−vis−NIR spectra of the three phases all exhibited a broad-band absorption over the entire visible light and extending into the near-infrared region, and the zinc-blende, wurtzite, and spinel Cu−In−S nanocrystals showed band gaps of 1.55, 1.54, and 1.51 eV, respectively, which indicates their potential applications in thin-film solar cells.

Rare-earth orthochromites are extremely interesting because of their potential applications as multifunctional materials. However, it is still a great challenge for the general synthesis of nanostructured full rare-earth orthochromites series. Here, a facile and versatile solvothermal reduction strategy is successfully employed in the preparation of rare-earth chromites with quasi-hollow nanostructures. X-ray diffraction data show that all the products have the orthorhombic perovskite structure. The electron microscopy analysis reveals that the morphology of the product is seriously affected by the rare-earth ionic radius. Tube-like and vesicle-like structures can be formed for the larger and smaller rare-earth cationic radii, respectively. The experimental results suggest that the roomtemperature precursors of potassium rare-earth chromates serve as a self-template for the in situ reduction and formation of rare-earth orthochromites hollow structures. The magnetization studies demonstrate that all the products, as it would be expected, undergo a magnetic transition from paramagnetic to antiferromagnetic phase at the Néel temperature (T N1 ) attributed to Cr 3+ -Cr 3+ exchange and this critical temperature goes up linearly with an increase in the rare-earth ionic radius.Additionally, some samples exhibit a variety of fancy magnetic properties, including thermal hysteresis suggesting a first-order magnetic transition, magnetization reversal due to the antiparallel polarization of the R 3+ paramagnetic moments by the Cr 3+ canted antiferromagnetic ones, and magnetic exchange bias related to the spin reorientation transition of the Cr 3+ magnetic moments. † Electronic supplementary information (ESI) available: XRD patterns and SEM images of the typical room-temperature intermediates; TEM images of the typical 1200 C annealing sample; SEM images of LaCrO 3 , PrCrO 3 , NdCrO 3 and SmCrO 3 before and aer annealing; summary of the magnetic data based on the temperature dependence of the magnetization for all samples. See

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Considerable efforts have been exerted on the controllable synthesis of columbite niobate ceramics due to their fascinating properties and applications. Especially, it is still a great challenge to fabricate nanostructures of the niobate series. In this research, FeNb 2 O 6 , CoNb 2 O 6 and NiNb 2 O 6 nanoparticles have been successfully prepared via a facile hydrothermal route followed by heat treatment. X-ray powder diffraction patterns show that all the products have the typical orthorhombic columbite structure. The electron microscopy analyses reveal that the obtained nanoparticles have diameters of 50-100 nm. The magnetic property results demonstrate that the magnetically ordered state is hard to observe down to 1.8 K for the FeNb 2 O 6 sample, while the magnetic transition temperatures of T N ¼ 3 K and T N ¼ 6 K can be obtained for CoNb 2 O 6 and NiNb 2 O 6 samples, respectively. A weak ferromagnetic moment can be detected below 5 K for both CoNb 2 O 6 and NiNb 2 O 6 samples. Furthermore, the NiNb 2 O 6 sample even exhibits a metamagnetic transition at 1.8 K due to the spin flipping of the ferromagnetic chains.

Considerable efforts have been exerted on the facile synthesis of magnetic composite materials because of their unique properties and potential applications. Especially for ferromagnetic-antiferromagnetic systems, the magnetic exchange bias effect is essential for the development of magneto-electronic switching devices and magnetic storage media. In this research, a facile ethylene glycol in situ reduction strategy has been successfully employed in the preparation of Ni-Cr 2 O 3 composite hollow spheres. X-Ray powder diffraction was used to determine the phase composition. Scanning electron microscopy and transmission electron microscopy was employed to characterize the morphologies of the as-prepared samples. Experiments proved that the volume ratio of ethylene glycol to water played a determinative role in the final morphology of the products. The magnetization vs. temperature results revealed a spin-glass-like behavior with blocking temperature of about 150 K for the as-prepared Ni-Cr 2 O 3 composites. Induced by the coupling between ferromagnetic Ni and antiferromagnetic Cr 2 O 3 , a small exchange bias effect could be observed in the magnetic hysteresis loops. At lower temperature, a larger exchange bias field and coercivity are obtained. A high surface area of 145.1 m 2 g −1 was obtained for the prepared porous hollow spheres.