Scanning tunnelling microscopy studies of α-Fe2O3(0001)

N. G. Condon; F. M. Leibsle; A. R. Lennie; P. W. Murray; T. M. Parker; D. J. Vaughan; G. Thornton

doi:10.1016/S0039-6028(97)00744-9

Scanning tunnelling microscopy studies of α-Fe₂O₃(0001)

N. G. Condon^*, F. M. Leibsle, A. R. Lennie, P. W. Murray, T. M. Parker, D. J. Vaughan, G. Thornton

^*Corresponding author for this work

Earth and Environmental Sciences - Academic & Research

Research output: Contribution to journal › Article › peer-review

Abstract

Scanning tunnelling microscopy (STM) images of two different reconstructions of an α-Fe₂O₃(0001) crystal are presented. Annealing the sample to 1000 K creates a selvedge stabilised by a thin film of Fe₃O₄, with its (111) plane parallel to the basal plane of the underlying substrate. The STM images confirm that this surface is structurally equivalent to that previously reported for the surface of Fe₃O₄(111) single crystals, in that two coexisting terminations, denoted A and B, are present separated by alternate steps. Termination A has been identified with 1/4 ML of O atoms capping 3/4 ML of Fe atoms, while termination B consists of 1/2 ML of Fe atoms overlaying a close-packed O layer. Some regions of the sample are disordered but contain small triangular islands of termination A. This structure is attributed to Ar ion induced sputter damage. A different termination, created by annealing the sample at 1100 K in 1 × 10^-6 mbar O₂, has a distinctive hexagonal LEED pattern, with all the main beams floreted, being surrounded by a hexagon of smaller spots. The STM results show that this surface is stabilized by coexisting α-Fe₂O₃(0001) and Fe_{1 - x}O(111) phases, with each phase existing in atomically well ordered islands of mesoscopic dimensions. The islands themselves are arranged to form a superlattice. The formation of this superlattice can be explained in terms of the lattice mismatch between the two types of oxygen sub-lattices.

Original language	English
Pages (from-to)	278-287
Number of pages	10
Journal	Surface Science
Volume	397
Issue number	1-3
DOIs	https://doi.org/10.1016/S0039-6028(97)00744-9
Publication status	Published - 1 Feb 1998

Keywords

iron oxide
low energy electron diffraction: Low index single crystal surfaces
scanning tunneling microscopy
surface structure

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10.1016/S0039-6028(97)00744-9

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@article{ac00030dfcd84b9fb48672dcc38df266,

title = "Scanning tunnelling microscopy studies of α-Fe2O3(0001)",

abstract = "Scanning tunnelling microscopy (STM) images of two different reconstructions of an α-Fe2O3(0001) crystal are presented. Annealing the sample to 1000 K creates a selvedge stabilised by a thin film of Fe3O4, with its (111) plane parallel to the basal plane of the underlying substrate. The STM images confirm that this surface is structurally equivalent to that previously reported for the surface of Fe3O4(111) single crystals, in that two coexisting terminations, denoted A and B, are present separated by alternate steps. Termination A has been identified with 1/4 ML of O atoms capping 3/4 ML of Fe atoms, while termination B consists of 1/2 ML of Fe atoms overlaying a close-packed O layer. Some regions of the sample are disordered but contain small triangular islands of termination A. This structure is attributed to Ar ion induced sputter damage. A different termination, created by annealing the sample at 1100 K in 1 × 10-6 mbar O2, has a distinctive hexagonal LEED pattern, with all the main beams floreted, being surrounded by a hexagon of smaller spots. The STM results show that this surface is stabilized by coexisting α-Fe2O3(0001) and Fe1 - xO(111) phases, with each phase existing in atomically well ordered islands of mesoscopic dimensions. The islands themselves are arranged to form a superlattice. The formation of this superlattice can be explained in terms of the lattice mismatch between the two types of oxygen sub-lattices.",

keywords = "iron oxide, low energy electron diffraction: Low index single crystal surfaces, scanning tunneling microscopy, surface structure",

author = "Condon, {N. G.} and Leibsle, {F. M.} and Lennie, {A. R.} and Murray, {P. W.} and Parker, {T. M.} and Vaughan, {D. J.} and G. Thornton",

note = "Funding Information: NGC was supported by the Company Research Laboratory of Brmsh Nuclear Fuels plc. Other funding for this work was prowded by the UK EPSRC and NERC",

year = "1998",

month = feb,

day = "1",

doi = "10.1016/S0039-6028(97)00744-9",

language = "English",

volume = "397",

pages = "278--287",

journal = "Surface Science",

issn = "0039-6028",

publisher = "Elsevier BV",

number = "1-3",

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TY - JOUR

T1 - Scanning tunnelling microscopy studies of α-Fe2O3(0001)

AU - Condon, N. G.

AU - Leibsle, F. M.

AU - Lennie, A. R.

AU - Murray, P. W.

AU - Parker, T. M.

AU - Vaughan, D. J.

AU - Thornton, G.

N1 - Funding Information: NGC was supported by the Company Research Laboratory of Brmsh Nuclear Fuels plc. Other funding for this work was prowded by the UK EPSRC and NERC

PY - 1998/2/1

Y1 - 1998/2/1

N2 - Scanning tunnelling microscopy (STM) images of two different reconstructions of an α-Fe2O3(0001) crystal are presented. Annealing the sample to 1000 K creates a selvedge stabilised by a thin film of Fe3O4, with its (111) plane parallel to the basal plane of the underlying substrate. The STM images confirm that this surface is structurally equivalent to that previously reported for the surface of Fe3O4(111) single crystals, in that two coexisting terminations, denoted A and B, are present separated by alternate steps. Termination A has been identified with 1/4 ML of O atoms capping 3/4 ML of Fe atoms, while termination B consists of 1/2 ML of Fe atoms overlaying a close-packed O layer. Some regions of the sample are disordered but contain small triangular islands of termination A. This structure is attributed to Ar ion induced sputter damage. A different termination, created by annealing the sample at 1100 K in 1 × 10-6 mbar O2, has a distinctive hexagonal LEED pattern, with all the main beams floreted, being surrounded by a hexagon of smaller spots. The STM results show that this surface is stabilized by coexisting α-Fe2O3(0001) and Fe1 - xO(111) phases, with each phase existing in atomically well ordered islands of mesoscopic dimensions. The islands themselves are arranged to form a superlattice. The formation of this superlattice can be explained in terms of the lattice mismatch between the two types of oxygen sub-lattices.

AB - Scanning tunnelling microscopy (STM) images of two different reconstructions of an α-Fe2O3(0001) crystal are presented. Annealing the sample to 1000 K creates a selvedge stabilised by a thin film of Fe3O4, with its (111) plane parallel to the basal plane of the underlying substrate. The STM images confirm that this surface is structurally equivalent to that previously reported for the surface of Fe3O4(111) single crystals, in that two coexisting terminations, denoted A and B, are present separated by alternate steps. Termination A has been identified with 1/4 ML of O atoms capping 3/4 ML of Fe atoms, while termination B consists of 1/2 ML of Fe atoms overlaying a close-packed O layer. Some regions of the sample are disordered but contain small triangular islands of termination A. This structure is attributed to Ar ion induced sputter damage. A different termination, created by annealing the sample at 1100 K in 1 × 10-6 mbar O2, has a distinctive hexagonal LEED pattern, with all the main beams floreted, being surrounded by a hexagon of smaller spots. The STM results show that this surface is stabilized by coexisting α-Fe2O3(0001) and Fe1 - xO(111) phases, with each phase existing in atomically well ordered islands of mesoscopic dimensions. The islands themselves are arranged to form a superlattice. The formation of this superlattice can be explained in terms of the lattice mismatch between the two types of oxygen sub-lattices.

KW - iron oxide

KW - low energy electron diffraction: Low index single crystal surfaces

KW - scanning tunneling microscopy

KW - surface structure

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U2 - 10.1016/S0039-6028(97)00744-9

DO - 10.1016/S0039-6028(97)00744-9

M3 - Article

AN - SCOPUS:0031990971

SN - 0039-6028

VL - 397

SP - 278

EP - 287

JO - Surface Science

JF - Surface Science

IS - 1-3

ER -

Scanning tunnelling microscopy studies of α-Fe₂O₃(0001)

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Keywords

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