Morphology Control of Nanostructures: Na-Doped PbTe-PbS System

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	Morphology Control of Nanostructures: Na-Doped PbTe-PbS System
	He, Jiaqing ; Blum, I. D. ; Wang, Hui-Qiong ; Girard, S. N. ; Doak, J. ; Zhao, Li-Dong ; Zheng, Jin-Cheng ; Casillas, G. ; Wolverton, C. ; Jose-Yacaman, M. ; Seidman, D. N. ; Kanatzidis, M. G. ; Dravid, V. P. ; Wang HQ(王惠琼)
刊名	http://dx.doi.org/10.1021/nl303449x
	2012-11
关键词	THERMOELECTRIC-MATERIALS SHAPE TRANSITIONS ENERGY PRECIPITATE PERFORMANCE INCLUSIONS NANOSCALE FIELD
英文摘要	Revolutionary Materials for Solid State Energy Conversion, an Energy Frontier Research Center; the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-SC0001054]; NSF-NSEC; NSF-MRSEC; Keck Foundation; State of Illinois; Northwestern University; NSF-MRI [DMR-0420532]; ONR-DURIP [N00014-0400798, N00014-0610539, N00014-0910781]; MRSEC program [DMR-1121262]; ISEN at Northwestern University; SRFDP [20090121120028, 20100121120026]; National Science Foundation of China [U1232110]; National Science Foundation (NSF) PREM [DMR-0934218]; The Morphology of Crystalline precipitates in,a solid-state matrix is governed: by complex but tractable energetic considerations driven largely by volume strain energy minimization and anisotropy of interfacial energies. Spherical precipitate morphologies are favored by isotropic systems, while anisotropic interfacial energies give energetic preference to certain crystallographically oriented interfaces, resulting in a faceted precipitate morphology. In conventional: solid-solution precipitation, a precipitate's morphological evolution. is mediated by surface anchoring of capping molecules, which dramatically alter the surface energy in an anisotropic manner, thereby providing exquisite morphology control: during crystal growth. Herein, we present. experimental evidence and theoretical validation for the role of a ternary element (Na) in controlling the morphology of nanoscale PbS-crystals nucleating in a PbTe matrix, an important bulk thermoelectric system. The PbS nanostructures formed by phase separation from a PbI2-doped or undoped PbTe matrix have irregular morphologies. However, replacing the iodine dopant With Na (1-2 mol %), alters dramatically the morphology of the PbS precipitates. Segregation of Na at PbTe/PbS interfaces result in cuboidal and truncated cuboidal morphologies for PbS: Using analytical scanning/transmission electron microscopy and atom-probe tomography, we demonstrate unambiguously that Na partitions to the precipitates and segregates at the matrix/precipitate interfaces, inducing morphological anisotropy of PbS precipitate's. First-principles and semiclassical calculations reveal that Na:as a solute in PbTe has a-higher energy than in PbS and that Na segregation at a (100) PhTe/PbS interface decreases the total. energy of matrix/precipitate system, resulting in faceting of PbS precipitates. These results provide an impetus for a new strategy, for controlling morphological evolution in matrix/precipitate systems, mediated by solute partitioning of ternary additions.
语种	英语
内容类型	期刊论文
源URL	[http://dspace.xmu.edu.cn/handle/2288/69657]
专题	物理技术－已发表论文
推荐引用方式 GB/T 7714	He, Jiaqing,Blum, I. D.,Wang, Hui-Qiong,et al. Morphology Control of Nanostructures: Na-Doped PbTe-PbS System[J]. http://dx.doi.org/10.1021/nl303449x,2012.
APA	He, Jiaqing.,Blum, I. D..,Wang, Hui-Qiong.,Girard, S. N..,Doak, J..,...&王惠琼.(2012).Morphology Control of Nanostructures: Na-Doped PbTe-PbS System.http://dx.doi.org/10.1021/nl303449x.
MLA	He, Jiaqing,et al."Morphology Control of Nanostructures: Na-Doped PbTe-PbS System".http://dx.doi.org/10.1021/nl303449x (2012).