Study of the mechano-chemical transformation of goethite to hematite by TEM and XRD

被引：69

作者：

González, G ^{[1
]}

Sagarzazu, A ^{[1
]}

Villalba, R ^{[1
]}

机构：

[1] Inst Venezolano Invest Cient, Ctr Technol, Mat Lab, Caracas 1020A, Venezuela

来源：

MATERIALS RESEARCH BULLETIN | 2000年 / 35卷 / 14-15期

关键词：

oxides; electron diffraction; electron microscopy; X-ray diffraction; defects;

D O I：

10.1016/S0025-5408(00)00434-7

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

A study of the mechano-chemical transformation of goethite to hematite was carried out using transmission electron microscopy (TEM) and X-ray diffraction (XRD). Synthetic goethite was dry-ground in air for different times up to 104 h and characterized with the aim of understanding the mechanisms taking part in the transformation, the phases formed, and particle distribution, morphology and size. It was found that the transformation is topotactic, without the formation of intermediate phases, and takes place by fragmentation of crystals, creation of twins, dehydration of goethite particles, and formation of voids. The voids are arranged in almost parallel striations, and are associated with the loss of hydroxyl groups and formation of hematite in small domains of equiaxial crystallites. The hematite crystal size is about 10 nm at the initial stages and after prolonged periods of grinding remains constant at about 19 nm. (C) 2001 Elsevier Science I,td. All rights reserved.

引用

页码：2295 / 2308

页数：14

共 14 条

[1]

DEFARIA JL, 1963, Z KRISTALLOGRAPHIE K, V119, P176

[2] PLASTIC DEFORMATION OF SINGLE CRYSTALS OF SAPPHIRE - BASAL SLIP AND TWINNING [J].

KRONBERG, ML .

ACTA METALLURGICA, 1957, 5 (09) :507-524

[3]

LAHOUSSE A, 1975, THESIS U LIBRE BRUXE

[4] REVIEW OF THE PHASE-TRANSFORMATION AND SYNTHESIS OF INORGANIC SOLIDS OBTAINED BY MECHANICAL TREATMENT (MECHANOCHEMICAL REACTIONS) [J].

LIN, IJ ;

NADIV, S .

MATERIALS SCIENCE AND ENGINEERING, 1979, 39 (02) :193-209

[5] INTERMEDIATE STATE OF DEHYDRATION OF SYNTHETIC GOETHITE [J].

MAEDA, Y ;

IGARASHI, M ;

TERADA, A ;

YOSHIMURA, F .

JAPANESE JOURNAL OF APPLIED PHYSICS, 1974, 13 (02) :381-382

[6] STRUCTURAL-ANALYSIS OF THE TRANSFORMATION MECHANISMS IN IRON-OXIDES AND OXYHYDROXIDES [J].

MATHIEU, F ;

ROUSSET, A .

PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES, 1993, 67 (03) :533-555

[7]

Megaw H.C., 1973, Crystal Structures: A Working Approach

[8] PROCESSINGS OF IRON-OXIDES AT ROOM-TEMPERATURE .1. SOLID-STATE CONVERSION OF PURE ALPHA-FEOOH INTO DISTINCTIVE ALPHA-FE2O3 [J].

MENDELOVICI, E ;

VILLALBA, R ;

SAGARZAZU, A .

MATERIALS RESEARCH BULLETIN, 1982, 17 (02) :241-249

[9] XRD study of the goethite-hematite transformation: application to the identification of heated prehistoric pigments [J].

Pomies, MP ;

Morin, G ;

Vignaud, C .

EUROPEAN JOURNAL OF SOLID STATE AND INORGANIC CHEMISTRY, 1998, 35 (01) :9-25

[10]

STEPHENSON JS, 1997, POWER METALL, V40, P100

← 1 2 →