Hu Yongming, Gu Haoshuang, Hu Zhenglong, Wang Hao
Key Lab of Ferro and Piezoelectric Materials and Devices of Hubei Province, Faculty of Physics and Electronic Technology, Hubei University, Wuhan 430062, PR China.
J Colloid Interface Sci. 2007 Jun 1;310(1):292-6. doi: 10.1016/j.jcis.2007.01.062. Epub 2007 Jan 31.
Two-dimensional KTa(0.77)Nb(0.23)O(3) (KTN) nanoplates with edge sizes of about 100 nm and thickness of about 10 nm have been fabricated by hydrothermal method at 200 degrees C using Ta(2)O(5), Nb(2)O(5), and KOH served as the precursors. Detailed structural studies indicate that the synthesized products are made up of large quantity single crystalline nanoplates with quadrilateral shape, which have a cubic perovskite structure without any other impurity phase and (011) growth direction. The stacking faults may be the key in the formation and growth of the (011) plate. Room temperature photoluminescence spectra excited at different wavelengths exhibit a strong emission band centered at 470 nm (2.63 eV) as well as two weak emission peaking at 423 nm (3.06 eV) and 505 nm (2.46 eV), respectively. The electron-hole recombination of localized excitons should responsible for the light emissions at 423 and 470 nm. Room temperature Raman spectrum of KTN nanoplates reveal that the frequencies of vibration mode are lower slightly than that of KTN bulk materials, and the scattering profile is to be more diffused and enlarged, which may be induced by the crystal structure defects, such as stacking faults.
采用水热法，以Ta₂O₅、Nb₂O₅和KOH为前驱体，在200℃下制备了边长约100nm、厚度约10nm的二维KTa(0.77)Nb(0.23)O₃（KTN）纳米片。详细的结构研究表明，合成产物由大量四边形形状的单晶纳米片组成，这些纳米片具有立方钙钛矿结构，没有任何其他杂质相，且生长方向为(011)。堆垛层错可能是(011)面纳米片形成和生长的关键因素。在不同波长激发下的室温光致发光光谱显示，有一个以470nm（2.63eV）为中心的强发射带，以及分别在423nm（3.06eV）和505nm（2.46eV）处的两个弱发射峰。局域激子的电子-空穴复合应是423nm和470nm处发光的原因。KTN纳米片的室温拉曼光谱表明，振动模式的频率略低于KTN块状材料，且散射轮廓更弥散、更宽，这可能是由晶体结构缺陷（如堆垛层错）引起的。
