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Title: Topotaxial growth of α-Fe{sub 2}O{sub 3} nanowires on iron substrate in thermal annealing method

Abstract

A detail cross-sectional transmission electron microscopy of as-grown α-Fe{sub 2}O{sub 3} nanowire sample, synthesized on iron substrate by thermal annealing method, was carried out to understand the mechanism of growth in this system. Iron undergoes sequential oxidation to form a layered structure of Fe/FeO/Fe{sub 3}O{sub 4}/α-Fe{sub 2}O{sub 3}. α-Fe{sub 2}O{sub 3} nanowires grow on to the top of α-Fe{sub 2}O{sub 3} layer. It was found that subsequent oxide layers grow topotaxially on the grains of iron, which results in a direct orientation relationship between the α-Fe{sub 2}O{sub 3} nanowire and the parent grain of iron. The results also showed that the grains of α-Fe{sub 2}O{sub 3} layer, which were uniquely oriented in [110] direction, undergo highly anisotropic growth to form the nanowire. This anisotropic growth occurs at a twin interface, given by (−11−1), in the α-Fe{sub 2}O{sub 3} layer. It was concluded that the growth at twin interface could be the main driving factor for such anisotropic growth. These observations are not only helpful in understanding the growth mechanism of α-Fe{sub 2}O{sub 3} nanowires, but it also demonstrates a way of patterning the nanowires by controlling the texture of iron substrate.

Authors:
; ; ; ;  [1]
  1. Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India)
Publication Date:
OSTI Identifier:
22596643
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 119; Journal Issue: 24; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANISOTROPY; ANNEALING; FERRITES; INTERFACES; IRON OXIDES; IRON-ALPHA; LAYERS; NANOWIRES; OXIDATION; SUBSTRATES; TRANSMISSION ELECTRON MICROSCOPY

Citation Formats

Srivastava, Himanshu, E-mail: himsri@rrcat.gov.in, Srivastava, A. K., Babu, Mahendra, Rai, Sanjay, and Ganguli, Tapas. Topotaxial growth of α-Fe{sub 2}O{sub 3} nanowires on iron substrate in thermal annealing method. United States: N. p., 2016. Web. doi:10.1063/1.4954975.
Srivastava, Himanshu, E-mail: himsri@rrcat.gov.in, Srivastava, A. K., Babu, Mahendra, Rai, Sanjay, & Ganguli, Tapas. Topotaxial growth of α-Fe{sub 2}O{sub 3} nanowires on iron substrate in thermal annealing method. United States. doi:10.1063/1.4954975.
Srivastava, Himanshu, E-mail: himsri@rrcat.gov.in, Srivastava, A. K., Babu, Mahendra, Rai, Sanjay, and Ganguli, Tapas. 2016. "Topotaxial growth of α-Fe{sub 2}O{sub 3} nanowires on iron substrate in thermal annealing method". United States. doi:10.1063/1.4954975.
@article{osti_22596643,
title = {Topotaxial growth of α-Fe{sub 2}O{sub 3} nanowires on iron substrate in thermal annealing method},
author = {Srivastava, Himanshu, E-mail: himsri@rrcat.gov.in and Srivastava, A. K. and Babu, Mahendra and Rai, Sanjay and Ganguli, Tapas},
abstractNote = {A detail cross-sectional transmission electron microscopy of as-grown α-Fe{sub 2}O{sub 3} nanowire sample, synthesized on iron substrate by thermal annealing method, was carried out to understand the mechanism of growth in this system. Iron undergoes sequential oxidation to form a layered structure of Fe/FeO/Fe{sub 3}O{sub 4}/α-Fe{sub 2}O{sub 3}. α-Fe{sub 2}O{sub 3} nanowires grow on to the top of α-Fe{sub 2}O{sub 3} layer. It was found that subsequent oxide layers grow topotaxially on the grains of iron, which results in a direct orientation relationship between the α-Fe{sub 2}O{sub 3} nanowire and the parent grain of iron. The results also showed that the grains of α-Fe{sub 2}O{sub 3} layer, which were uniquely oriented in [110] direction, undergo highly anisotropic growth to form the nanowire. This anisotropic growth occurs at a twin interface, given by (−11−1), in the α-Fe{sub 2}O{sub 3} layer. It was concluded that the growth at twin interface could be the main driving factor for such anisotropic growth. These observations are not only helpful in understanding the growth mechanism of α-Fe{sub 2}O{sub 3} nanowires, but it also demonstrates a way of patterning the nanowires by controlling the texture of iron substrate.},
doi = {10.1063/1.4954975},
journal = {Journal of Applied Physics},
number = 24,
volume = 119,
place = {United States},
year = 2016,
month = 6
}
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