Nucleation and Growth in Structural Transformations of Nanocrystals

被引：40

作者：

Gruenwald, Michael ^{[1
]}

Dellago, Christoph

机构：

[1] Univ Vienna, Fac Phys, A-1090 Vienna, Austria

来源：

NANO LETTERS | 2009年 / 9卷 / 05期

基金：

奥地利科学基金会;

关键词：

ROCK-SALT TRANSITION; CDSE NANOCRYSTALS; HIGH-PRESSURE; PHASE-TRANSITION; WURTZITE; METASTABILITY; SIZE; SIMULATION; MECHANISM; SILICON;

D O I：

10.1021/nl900609d

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Using transition path sampling computer simulations, we reveal the nucleation mechanism of a pressure-induced structural transformation in CdSe nanocrystals. Consistent with experiments, the thermodynamic transition pressure of the transformation increases with decreasing crystal size. Through transition state analysis, we identify the critical nuclei and characterize them by calculating activation enthalpies and volumes. Our simulations reproduce the trends with crystal size observed in experiments. This result supports the observed transformation mechanism, which consists of nucleation on the crystal surface and growth by sliding of parallel crystal planes.

引用

收藏

页码：2099 / 2102

页数：4

相关论文

共 28 条

[1] HIGH-PRESSURE PHASE-TRANSITION AND PHASE-DIAGRAM OF GALLIUM-ARSENIDE [J].

BESSON, JM ;

ITIE, JP ;

POLIAN, A ;

WEILL, G ;

MANSOT, JL ;

GONZALEZ, J .

PHYSICAL REVIEW B, 1991, 44 (09) :4214-4234

[2] Walking the path from B4- to B1-type structures in GaN [J].

Boulfelfel, S. E. ;

Zahn, D. ;

Grin, Yu. ;

Leoni, S. .

PHYSICAL REVIEW LETTERS, 2007, 99 (12)

[3] Theoretical metastability of semiconductor crystallites in high-pressure phases, with application to beta-tin structure silicon [J].

Brus, LE ;

Harkless, JAW ;

Stillinger, FH .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1996, 118 (20) :4834-4838

[4] Size dependence of structural metastability in semiconductor nanocrystals [J].

Chen, CC ;

Herhold, AB ;

Johnson, CS ;

Alivisatos, AP .

SCIENCE, 1997, 276 (5311) :398-401

[5] Transition path sampling and the calculation of rate constants [J].

Dellago, C ;

Bolhuis, PG ;

Csajka, FS ;

Chandler, D .

JOURNAL OF CHEMICAL PHYSICS, 1998, 108 (05) :1964-1977

[6] Transition path sampling [J].

Dellago, C ;

Bolhuis, PG ;

Geissler, PL .

ADVANCES IN CHEMICAL PHYSICS, VOL 123, 2002, 123 :1-78

[7] Ideal gas pressure bath:: a method for applying hydrostatic pressure in the computer simulation of nanoparticles [J].

Gruenwald, M. ;

Dellago, C. .

MOLECULAR PHYSICS, 2006, 104 (22-24) :3709-3715

[8] Mechanisms of the wurtzite to rocksalt transformation in CdSe nanocrystals [J].

Gruenwald, Michael ;

Rabani, Eran ;

Dellago, Christoph .

PHYSICAL REVIEW LETTERS, 2006, 96 (25)

[9] An efficient transition path sampling algorithm for nanoparticles under pressure [J].

Gruenwald, Michael ;

Dellago, Christoph .

JOURNAL OF CHEMICAL PHYSICS, 2007, 127 (15)

[10]

Hill T. L., 1994, Thermodynamics of Small Systems