Pressure induced phase transition of nanocrystalline and bulk maghemite (γ-Fe2O3) to hematite (α-Fe2O3)

被引：25

作者：

Zhu, Hongyang ^{[1
,2
]}

Ma, Yanzhang ^{[1
]}

Yang, Haibin ^{[2
]}

Ji, Cheng ^{[1
]}

Hou, Dongbin ^{[1
]}

Guo, Lingyun ^{[1
]}

机构：

[1] Texas Tech Univ, Dept Mech Engn, Lubbock, TX 79409 USA

[2] Jilin Univ, Natl Lab Superhard Mat, Changchun 130012, Jilin, Peoples R China

来源：

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS | 2010年 / 71卷 / 08期

关键词：

High Pressure; X-ray diffraction; X-RAY-DIFFRACTION; STRUCTURAL TRANSITIONS; SIZE DEPENDENCE; TRANSFORMATION; NANOPARTICLES; SPECTROSCOPY; STABILITY; MOSSBAUER;

D O I：

10.1016/j.jpcs.2010.03.031

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Phase transition and bulk moduli of bulk and nanocrystalline gamma-Fe2O3 were studied using synchrotron X-ray diffraction under high pressure. Contrary to most other nanomaterials, nanocrystalline gamma-Fe2O3 begins to transform into alpha-Fe2O3 at the same pressure as bulk gamma-Fe2O3, which is caused by a special structure of gamma-Fe2O3, in which there exist vacancies of crystal. It is believed that phase transition starts from a certain site of vacancy because of the stress concentration at vacancy sites. Compared to bulk material, nanocrystalline gamma-Fe2O3 has a larger bulk modulus, which is ascribed to the large ratio of surface to volume. (C) 2010 Elsevier Ltd. All rights reserved.

引用

页码：1183 / 1186

页数：4

共 29 条

[1] MOSSBAUER STUDY OF FERRIC IONS IN TETRAHEDRAL AND OCTAHEDRAL SITES OF A SPINEL [J].

ARMSTRONG, RJ ;

MORRISH, AH ;

SAWATZKY, GA .

PHYSICS LETTERS, 1966, 23 (07) :414-+

[2] FINITE ELASTIC STRAIN OF CUBIC CRYSTALS [J].

BIRCH, F .

PHYSICAL REVIEW, 1947, 71 (11) :809-824

[3] Crystallite nanosize effect on the structural transitions of WO3 studied by Raman spectroscopy [J].

Boulova, M ;

Lucazeau, G .

JOURNAL OF SOLID STATE CHEMISTRY, 2002, 167 (02) :425-434

[4] Size dependence of the pressure-induced γ to α structural phase transition in iron oxide nanocrystals [J].

Clark, SM ;

Prilliman, SG ;

Erdonmez, CK ;

Alivisatos, AP .

NANOTECHNOLOGY, 2005, 16 (12) :2813-2818

[5]

COLVIN VL, 1994, NATURE, V370, P354, DOI 10.1038/370354a0

[6] MAGNETIC STRUCTURE AND VACANCY DISTRIBUTION IN GAMMA-FE2O3 BY NEUTRON DIFFRACTION [J].

FERGUSON, GA ;

HASS, M .

PHYSICAL REVIEW, 1958, 112 (04) :1130-1131

[7] Magnetic nanoparticles with enhanced γ-Fe2O3 to α-Fe2O3 phase transition temperature [J].

Gnanaprakash, G. ;

Ayyappan, S. ;

Jayakumar, T. ;

Philip, John ;

Raj, Baldev .

NANOTECHNOLOGY, 2006, 17 (23) :5851-5857

[8] DIAMOND ANVIL CELL AND HIGH-PRESSURE PHYSICAL INVESTIGATIONS [J].

JAYARAMAN, A .

REVIEWS OF MODERN PHYSICS, 1983, 55 (01) :65-108

[9] Structural stability in nanocrystalline ZnO [J].

Jiang, JZ ;

Olsen, JS ;

Gerward, L ;

Frost, D ;

Rubie, D ;

Peyronneau, J .

EUROPHYSICS LETTERS, 2000, 50 (01) :48-53

[10] Grain-size effect on pressure-induced semiconductor-to-metal transition in ZnS [J].

Jiang, JZ ;

Gerward, L ;

Frost, D ;

Secco, R ;

Peyronneau, J ;

Olsen, JS .

JOURNAL OF APPLIED PHYSICS, 1999, 86 (11) :6608-6610

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