http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
A. T. Raghavender,Sagar E. Shirsath,D. Pajic,K. Zadro,T. Milekovic,K. M. Jadhav,K. Vijaya Kumar 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.61 No.4
Nanocrystalline CuFe<sub>2-x</sub>Al<sub>x</sub>O<sub>4</sub> (0.0 ≤ x ≤ 1.0) was synthesized by sol-gel method and their structural and magnetic properties were investigated. The crystallite size was observed to decrease from 20 to 6 nm with increasing Al content. The lattice parameters were observed to decrease with increasing Al content. The cation distribution from X-ray intensity calculations revealed that Cu<sup>2+</sup> preferably occupy octahedral [B] sites. Al<sup>3+</sup> ions replace the Fe<sup>3+</sup> ions in the tetrahedral (A) and octahedral [B] sites. As a result the Fe<sup>3+</sup> concentration at (A) and [B] sites decreases leading to the suppression of long range magnetic ordering. Magnetic hysteresis loops were measured at room temperature with a maximum applied magnetic field of ≒1 T. As Al<sup>3+</sup> content increases, the measured magnetic hysteresis curves become more and more narrow and the saturation magnetization and remanent magnetization both decreased. The reduction of magnetization with increase of aluminum content is caused by non-magnetic Al<sup>3+</sup> ions and weakened interaction between sub-lattices. The reduction of magnetization compared to bulk may originate from the smallness of particles. This is accompanied also with coercive field reduction.
A Facile and TGA Free Hydrothermal Synthesis of SnS Nanoparticles
Y. P. Venkata Subbaiah,Narayana Thota,M. Raghavender,Y. P. Venkata Subbaiah,G. Hema Chandra,K.T. Ramakrishna Reddy 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.10
"In this paper, we employed a simple and cost-effective thioglycolic acid (TGA) free hydrothermal method, based on thiourea hydrolysis of stannous chloride dihydrate [SnCl2 · 2H2O] at 160 ℃ – 190 ℃ for 6 h, for the synthesis of SnS nanoparticles. The effect of hydrothermal autoclave reaction temperature on various properties of SnS nanoparticles have been examined at length using X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy attached with EDAX (FE-SEM), transmission electron microscopy (TEM) and ultraviolet-visible (UV-Vis) spectroscopy. The results suggest that the crystallization of orthorhombic SnS nanoparticles, with size varying from 3 nm to 5 nm, formed at RT = 160 ℃. Further, the formation of SnS phase was confirmed by an IR Sn-S characteristic bands around 2350 cm -1, 1041 cm -1 and 570 cm -1, and four distinguished Raman peaks at 95 cm -1, 160 cm -1, 189 cm -1 and 220 cm -1. The mechanism for the formation of SnS nanoparticles have been proposed and discussed. The SnS nanoparticles have exhibited reaction temperature dependent morphological features like nanoflowers, nanoflakes, spherical nanoparticles and nanogranules. The absorbance studies indicated both strong direct and weak indirect allowed transitions for SnS nanoparticles and the associated band gaps were found to be 1.5 eV and 1.19 eV, respectively. The dual band gap combination of SnS would favor strong direct absorption of carriers and improved minority carrier life time due to indirect nature, which means the grown particles are suitable for ideal absorber material for solar cell applications. "