Evidence for charge ordering at room temperature in Fe3O4

M. L. Rudee, David Smith, D. T. Margulies

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

A previously unknown form of charge ordering has been observed in magnetite, Fe3O4, a material that is currently studied for possible use in the emerging field of magnetic multilayer devices. In many crystalline materials, electrons are more or less localized on specific lattice sites. In some such cases, longer range fluctuations in electron density known as charge-density waves or charge ordering also occur. Charge ordering is usually associated with structures that have a well-defined two-dimensional layer structure, and the periodicity of the charge ordering is often irregularly related to the basic structural repeat unit. We report observations at room temperature and above of a new form of charge ordering in thin films of magnetite, which has a cubic, rather than a layered, structure. We show that this phenomenon of charge ordering on tetrahedral sites is unrelated to the well-known low-temperature ordering on octahedral sites that occurs below 120 K. From electron-diffraction patterns we deduce the magnitude and crystallographic orientation of the fluctuations, and find they are a regular multiple of the underlying structure. In addition, we present electron micrographs in which the charge ordering is visible, and which clearly show disorganized boundaries between regions of regularly arranged charge ordering. We believe that ordering of this type in magnetite may not have been observed previously because of insufficient purity and perfection of the materials studied. However, we suspect that similar charge ordering is likely in other metal oxides of high crystal quality where metal ions have mixed-valence states.

Original languageEnglish (US)
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume59
Issue number18
StatePublished - May 1 1999

Fingerprint

Ferrosoferric Oxide
Magnetite
magnetite
room temperature
Magnetic multilayers
Charge density waves
Electrons
Electron diffraction
Temperature
Oxides
Diffraction patterns
Carrier concentration
Metal ions
metal oxides
periodic variations
emerging
metal ions
purity
electrons
diffraction patterns

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Evidence for charge ordering at room temperature in Fe3O4 . / Rudee, M. L.; Smith, David; Margulies, D. T.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 59, No. 18, 01.05.1999.

Research output: Contribution to journalArticle

@article{7ea918f4b2744b348d2ac1f0947108bc,
title = "Evidence for charge ordering at room temperature in Fe3O4",
abstract = "A previously unknown form of charge ordering has been observed in magnetite, Fe3O4, a material that is currently studied for possible use in the emerging field of magnetic multilayer devices. In many crystalline materials, electrons are more or less localized on specific lattice sites. In some such cases, longer range fluctuations in electron density known as charge-density waves or charge ordering also occur. Charge ordering is usually associated with structures that have a well-defined two-dimensional layer structure, and the periodicity of the charge ordering is often irregularly related to the basic structural repeat unit. We report observations at room temperature and above of a new form of charge ordering in thin films of magnetite, which has a cubic, rather than a layered, structure. We show that this phenomenon of charge ordering on tetrahedral sites is unrelated to the well-known low-temperature ordering on octahedral sites that occurs below 120 K. From electron-diffraction patterns we deduce the magnitude and crystallographic orientation of the fluctuations, and find they are a regular multiple of the underlying structure. In addition, we present electron micrographs in which the charge ordering is visible, and which clearly show disorganized boundaries between regions of regularly arranged charge ordering. We believe that ordering of this type in magnetite may not have been observed previously because of insufficient purity and perfection of the materials studied. However, we suspect that similar charge ordering is likely in other metal oxides of high crystal quality where metal ions have mixed-valence states.",
author = "Rudee, {M. L.} and David Smith and Margulies, {D. T.}",
year = "1999",
month = "5",
day = "1",
language = "English (US)",
volume = "59",
journal = "Physical Review B-Condensed Matter",
issn = "0163-1829",
publisher = "American Institute of Physics Publising LLC",
number = "18",

}

TY - JOUR

T1 - Evidence for charge ordering at room temperature in Fe3O4

AU - Rudee, M. L.

AU - Smith, David

AU - Margulies, D. T.

PY - 1999/5/1

Y1 - 1999/5/1

N2 - A previously unknown form of charge ordering has been observed in magnetite, Fe3O4, a material that is currently studied for possible use in the emerging field of magnetic multilayer devices. In many crystalline materials, electrons are more or less localized on specific lattice sites. In some such cases, longer range fluctuations in electron density known as charge-density waves or charge ordering also occur. Charge ordering is usually associated with structures that have a well-defined two-dimensional layer structure, and the periodicity of the charge ordering is often irregularly related to the basic structural repeat unit. We report observations at room temperature and above of a new form of charge ordering in thin films of magnetite, which has a cubic, rather than a layered, structure. We show that this phenomenon of charge ordering on tetrahedral sites is unrelated to the well-known low-temperature ordering on octahedral sites that occurs below 120 K. From electron-diffraction patterns we deduce the magnitude and crystallographic orientation of the fluctuations, and find they are a regular multiple of the underlying structure. In addition, we present electron micrographs in which the charge ordering is visible, and which clearly show disorganized boundaries between regions of regularly arranged charge ordering. We believe that ordering of this type in magnetite may not have been observed previously because of insufficient purity and perfection of the materials studied. However, we suspect that similar charge ordering is likely in other metal oxides of high crystal quality where metal ions have mixed-valence states.

AB - A previously unknown form of charge ordering has been observed in magnetite, Fe3O4, a material that is currently studied for possible use in the emerging field of magnetic multilayer devices. In many crystalline materials, electrons are more or less localized on specific lattice sites. In some such cases, longer range fluctuations in electron density known as charge-density waves or charge ordering also occur. Charge ordering is usually associated with structures that have a well-defined two-dimensional layer structure, and the periodicity of the charge ordering is often irregularly related to the basic structural repeat unit. We report observations at room temperature and above of a new form of charge ordering in thin films of magnetite, which has a cubic, rather than a layered, structure. We show that this phenomenon of charge ordering on tetrahedral sites is unrelated to the well-known low-temperature ordering on octahedral sites that occurs below 120 K. From electron-diffraction patterns we deduce the magnitude and crystallographic orientation of the fluctuations, and find they are a regular multiple of the underlying structure. In addition, we present electron micrographs in which the charge ordering is visible, and which clearly show disorganized boundaries between regions of regularly arranged charge ordering. We believe that ordering of this type in magnetite may not have been observed previously because of insufficient purity and perfection of the materials studied. However, we suspect that similar charge ordering is likely in other metal oxides of high crystal quality where metal ions have mixed-valence states.

UR - http://www.scopus.com/inward/record.url?scp=0001630869&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0001630869&partnerID=8YFLogxK

M3 - Article

VL - 59

JO - Physical Review B-Condensed Matter

JF - Physical Review B-Condensed Matter

SN - 0163-1829

IS - 18

ER -