Colossal Magnetoresistance without Mixed Valence in a Layered Phosphide Crystal

A-Site Distribution in La1−xSrxMnO3: a Computational Study

MRS Proceedings ◽

10.1557/proc-1074-i02-10 ◽

2008 ◽

Vol 1074 ◽

Author(s):

Yun Hee Jang ◽

François Gervais ◽

Yves Lansac

Keyword(s):

Molecular Dynamics ◽

Quantum Mechanics ◽

Colossal Magnetoresistance ◽

Computational Study ◽

Mixed Valence ◽

Magnetic Tunnel Junction ◽

Md Simulations ◽

Site Distribution ◽

Mixed Valence Manganites ◽

A Site

ABSTRACTThe possibility of an A-site (La3+/Sr2+) ordering in a colossal magnetoresistance manganite (CMR) La3/4Sr1/4MnO3 was explored using molecular dynamics (MD) simulations with a newly developed force field (FF) and quantum mechanics (QM) calculations on the structures obtained from MD. The calculated degrees of stabilization (enthalpy gain) of various patterns of A-site ordering are not significant enough to overcome the accompanying entropy loss, supporting the random A-site distribution in La3/4Sr1/4MnO3. This approach combining MD and QM as well as the versatile FF developed in this study should be useful to investigate the structures and functions of magnetic tunnel junction devices involving mixed-valence manganites.

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Thermal expansion and magnetostriction in colossal magnetoresistance mixed valence manganites (abstract)

Journal of Applied Physics ◽

10.1063/1.364583 ◽

1997 ◽

Vol 81 (8) ◽

pp. 5504-5504 ◽

Cited By ~ 3

Author(s):

J. M. De Teresa ◽

M. R. Ibarra ◽

P. A. Algarabel ◽

C. Marquina ◽

J. Blasco ◽

...

Keyword(s):

Thermal Expansion ◽

Colossal Magnetoresistance ◽

Mixed Valence ◽

Mixed Valence Manganites

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Manganites

Superconducting State ◽

10.1093/oso/9780198845331.003.0009 ◽

2021 ◽

pp. 403-428

Author(s):

Vladimir Z. Kresin ◽

Sergei G. Ovchinnikov ◽

Stuart A. Wolf

Keyword(s):

Colossal Magnetoresistance ◽

Mixed Valence ◽

Fundamental Property ◽

Microscopic Theory ◽

Double Exchange ◽

Metallic State ◽

Electron Hole ◽

Jahn Teller ◽

Jahn Teller Effect ◽

Mixed Valence Compounds

This chapter focuses on manganites. There is a large similarity between the two families of mixed-valence compounds, the cuprates and the manganites. However, manganites display colossal magnetoresistance. The most fundamental property of manganites is the strong correlation between their transport properties and their magnetic properties. This correlation is caused by the double-exchange mechanism. The Hund interaction and the Jahn–Teller effect are the key ingredients of the microscopic theory. The transition to the ferromagnetic and metallic state is of a percolative nature. The superconducting–antiferromagnetic–superconducting Josephson junction is described. One can observe giant oscillations of the Josephson current as a function of a weak external magnetic field. The main properties, including the electron–hole asymmetry can be described in the framework of a generalised two-band picture. A peculiar isotope effect can be observed.

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The crucial role of mixed valence in the magnetoresistance properties of manganites and cobaltites

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2007.2141 ◽

2007 ◽

Vol 366 (1862) ◽

pp. 83-92 ◽

Cited By ~ 28

Author(s):

B Raveau

Keyword(s):

Colossal Magnetoresistance ◽

Mixed Valence ◽

Transition Element ◽

Oxygen Stoichiometry ◽

Orbital Ordering ◽

Electronic Phase ◽

Spin Glass Behaviour ◽

Jahn Teller ◽

Jahn Teller Effect

The mixed valence Mn 3+ /Mn 4+ and Co 3+ /Co 4+ in manganites and cobaltites with the perovskite structure is absolutely necessary for the appearance of magnetotransport properties. It is shown that in these systems the Jahn Teller effect of the transition element, the charge and orbital ordering and the oxygen stoichiometry play a key role in the appearance of large and even colossal magnetoresistance. It has been discovered that these oxides exhibit a new phenomenon, the crystallographic and electronic phase separation. It is this phenomenon that is at the origin of the competition between ferromagnetism and antiferromagnetism or spin glass behaviour and which leads to the negative magnetoresistance (MR). The doping of these materials at different sites appears then to be a means of inducing large MR effects.

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Unconventional Colossal Magnetoresistance in Sodium Chromium Oxide with a Mixed-Valence State

Angewandte Chemie ◽

10.1002/ange.201201884 ◽

2012 ◽

Vol 124 (27) ◽

pp. 6757-6760 ◽

Cited By ~ 4

Author(s):

Hiroya Sakurai ◽

Taras Kolodiazhnyi ◽

Yuichi Michiue ◽

Eiji Takayama-Muromachi ◽

Yuichi Tanabe ◽

...

Keyword(s):

Chromium Oxide ◽

Valence State ◽

Colossal Magnetoresistance ◽

Mixed Valence ◽

Mixed Valence State

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ChemInform Abstract: Unconventional Colossal Magnetoresistance in Sodium Chromium Oxide with a Mixed-Valence State.

ChemInform ◽

10.1002/chin.201240009 ◽

2012 ◽

Vol 43 (40) ◽

pp. no-no

Author(s):

Hiroya Sakurai ◽

Taras Kolodiazhnyi ◽

Yuichi Michiue ◽

Eiji Takayama-Muromachi ◽

Yuichi Tanabe ◽

...

Keyword(s):

Chromium Oxide ◽

Valence State ◽

Colossal Magnetoresistance ◽

Mixed Valence ◽

Mixed Valence State

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Unconventional Colossal Magnetoresistance in Sodium Chromium Oxide with a Mixed-Valence State

Angewandte Chemie International Edition ◽

10.1002/anie.201201884 ◽

2012 ◽

Vol 51 (27) ◽

pp. 6653-6656 ◽

Cited By ~ 28

Author(s):

Hiroya Sakurai ◽

Taras Kolodiazhnyi ◽

Yuichi Michiue ◽

Eiji Takayama-Muromachi ◽

Yuichi Tanabe ◽

...

Keyword(s):

Chromium Oxide ◽

Valence State ◽

Colossal Magnetoresistance ◽

Mixed Valence ◽

Mixed Valence State

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John Goodenough and the Many Lives of Transition-Metal Oxides

Journal of The Electrochemical Society ◽

10.1149/1945-7111/ac4895 ◽

2022 ◽

Author(s):

John M. Tranquada

Keyword(s):

High Temperature ◽

Transition Metal ◽

Metal Oxides ◽

Transition Metal Oxides ◽

Colossal Magnetoresistance ◽

High Temperature Superconductivity ◽

Mixed Valence ◽

Wide Range ◽

The Many

Abstract In honor of John Goodenough's centennial birthday, I discuss some of his insights into magnetism and the role of mixed valence in transition-metal oxides. His ideas form an important part of the continuing evolution of our understanding of these fascinating materials with a wide range of technologically-important functionalities. In particular, will mention connections to phenomena such as colossal magnetoresistance, enhanced thermopower, and high-temperature superconductivity.

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