skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Structural phase diagram for ultra-thin epitaxial Fe3O4 / MgO(0 01) films: thickness and oxygen pressure dependence

Journal Article · · Journal of Physics. Condensed Matter
 [1];  [1];  [1];  [2];  [1]
  1. Univ. of Connecticut, Storrs, CT (United States)
  2. Brookhaven National Lab. (BNL), Upton, NY (United States)
+ Show Author Affiliations

A systematic investigation of the thickness and oxygen pressure dependence for the structural properties of ultra-thin epitaxial magnetite (Fe3O4) films has been carried out; for such films, the structural properties generally differ from those for the bulk when the thickness ≤10 nm. Iron oxide ultra-thin films with thicknesses varying from 3 nm to 20 nm were grown on MgO (001) substrates using molecular beam epitaxy under different oxygen pressures ranging from 1 × 10-7 torr to 1 × 10-5 torr. The crystallographic and electronic structures of the films were characterized using low energy electron diffraction (LEED) and x-ray photoemission spectroscopy (XPS), respectively. Moreover, the quality of the epitaxial Fe3O4 ultra-thin films was judged by magnetic measurements of the Verwey transition, along with complementary XPS spectra. We observed that under the same growth conditions the stoichiometry of ultra-thin films under 10 nm transforms from the Fe3O4 phase to the FeO phase. In this work, a phase diagram based on thickness and oxygen pressure has been constructed to explain the structural phase transformation. It was found that high-quality magnetite films with thicknesses ≤20 nm formed within a narrow range of oxygen pressure. An optimal and controlled growth process is a crucial requirement for the accurate study of the magnetic and electronic properties for ultra-thin Fe3O4 films. Furthermore, these results are significant because they may indicate a general trend in the growth of other oxide films, which has not been previously observed or considered.

Research Organization:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
SC00112704; No. DE-SC00112704
OSTI ID:
1248806
Alternate ID(s):
OSTI ID: 1238405
Report Number(s):
BNL-112061-2016-JA; R&D Project: PO010; KC0201060
Journal Information:
Journal of Physics. Condensed Matter, Vol. 28, Issue 11; ISSN 0953-8984
Publisher:
IOP PublishingCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 17 works
Citation information provided by
Web of Science

References (29)

Effects of oxygen annealing on the physical properties and surface microstructures of La 0.8 Ba 0.2 MnO 3 films journal November 2002
Analysis of the Verwey transition in magnetite journal October 1995
Oxygen pressure and thickness dependent lattice strain in La[sub 0.7]Sr[sub 0.3]MnO[sub 3] films journal January 2003
Structural and magnetic properties of magnetite-containing epitaxial iron oxide films grown on MgO(001) substrates journal February 2008
From epitaxial growth of ferrite thin films to spin-polarized tunnelling journal March 2013
Origin of metal–insulator transition temperature enhancement in underdoped lanthanum manganite films journal March 2003
Synthesis of epitaxial films of Fe3O4 and α-Fe2O3 with various low-index orientations by oxygen-plasma-assisted molecular beam epitaxy journal March 1997
Material characteristics of perovskite manganese oxide thin films for bolometric applications journal October 1997
Magnetic and transport properties of epitaxial Fe 3 O 4 films grown at different oxygen pressure journal June 2015
Epitaxial growth of iron oxide films on Ag(111) journal January 2005
Growth of iron oxides on Ag(111) — Reversible Fe2O3/Fe3O4 transformation journal December 2011
X-ray diffraction study on size effects in epitaxial magnetite thin films on MgO(0 0 1) journal September 2012
Observation of the Verwey transition in thin magnetite films journal June 2005
Electronic Conduction of Magnetite (Fe3O4) and its Transition Point at Low Temperatures journal August 1939
Verwey transition in Fe 3 O 4 thin films: Influence of oxygen stoichiometry and substrate-induced microstructure journal September 2014
Origin of the giant magnetic moment in epitaxial Fe 3 O 4 thin films journal April 2010
X-Ray Diffraction Study on the Low Temperature Phase of Magnetite journal January 1977
Influence of nonstoichiometry on the Verwey transition journal January 1985
Effect of low-level titanium(IV) doping on the resistivity of magnetite near the Verwey transition journal July 1992
Stoichiometry, percolation, and Verwey ordering in magnetite journal March 1993
Impurity effects upon the Verwey transition in magnetite journal December 1998
Preparation and characterization of epitaxial iron oxide films journal July 1998
An STM study of Fe3O4(100) grown by molecular beam epitaxy journal February 1997
Growth And Structure Of Nanometric Iron Oxide Films journal January 1998
Atomic-oxygen-assisted MBE growth of α − F e 2 O 3 on α − A l 2 O 3 (0001): Metastable FeO(111)-like phase at subnanometer thicknesses journal November 1999
Structural properties of epitaxial nanometric iron oxide layers on α-Al2O3(0001): an in situ RHEED study during growth journal May 2000
Heteroepitaxial growth of α-Fe2O3, γ-Fe2O3 and Fe3O4 thin films by oxygen-plasma-assisted molecular beam epitaxy journal April 1997
In situ XPS analysis of various iron oxide films grown by NO 2 -assisted molecular-beam epitaxy journal January 1999
Growth of iron oxide on Cu(001) at elevated temperature journal November 1999

Cited By (1)

Evolution of magnetic properties in the vicinity of the Verwey transition in Fe 3 O 4 thin films journal September 2017

Similar Records

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY