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Title: Hybrid excitations due to crystal field, spin-orbit coupling, and spin waves in LiFePO 4

Abstract

Here, we report on the spin waves and crystal field excitations in single crystal LiFePO 4 by inelastic neutron scattering over a wide range of temperatures, below and above the antiferromagnetic transition of this system. In particular, we find extra excitations below T N = 50 K that are nearly dispersionless and are most intense around magnetic zone centers. Furthermore, we show that these excitations correspond to transitions between thermally occupied excited states of Fe 2 + due to splitting of the S = 2 levels that arise from the crystal field and spin-orbit interactions. These excitations are further amplified by the highly distorted nature of the oxygen octahedron surrounding the iron atoms. Above T N , magnetic fluctuations are observed up to at least 720 K, with an additional inelastic excitation around 4 meV, which we attribute to single-ion effects, as its intensity weakens slightly at 720 K compared to 100 K, which is consistent with the calculated cross sections using a single-ion model. This theoretical analysis, using the MF-RPA model, provides both detailed spectra of the Fe d shell and estimates of the average ordered magnetic moment and T N . By applying the MF-RPA model to amore » number of existing spin-wave results from other Li M PO 4 ( M = Mn , Co, and Ni), we are able to obtain reasonable predictions for the moment sizes and transition temperatures.« less

Authors:
 [1];  [2];  [3];  [4];  [1];  [1]
  1. Iowa State Univ., Ames, IA (United States). Dept. of Materials Science and Engineering (DMSE)
  2. Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab., ISIS Neutron Source
  3. Helmholtz-Zentrum Berlin (HZB), (Germany). German Research Centre for Materials and Energy
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Quantum Condensed Matter Division
Publication Date:
Research Org.:
Ames Laboratory (AMES), Ames, IA (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1355753
Alternate Identifier(s):
OSTI ID: 1346433; OSTI ID: 1361313
Report Number(s):
IS-J 9306
Journal ID: ISSN 2469-9950; PRBMDO; TRN: US1702604
Grant/Contract Number:  
AC02-07CH11358; AC05-00OR22725
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 95; Journal Issue: 10; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Yiu, Yuen, Le, Manh Duc, Toft-Peterson, Rasmus, Ehlers, Georg, McQueeney, Robert J., and Vaknin, David. Hybrid excitations due to crystal field, spin-orbit coupling, and spin waves in LiFePO4. United States: N. p., 2017. Web. doi:10.1103/PhysRevB.95.104409.
Yiu, Yuen, Le, Manh Duc, Toft-Peterson, Rasmus, Ehlers, Georg, McQueeney, Robert J., & Vaknin, David. Hybrid excitations due to crystal field, spin-orbit coupling, and spin waves in LiFePO4. United States. doi:10.1103/PhysRevB.95.104409.
Yiu, Yuen, Le, Manh Duc, Toft-Peterson, Rasmus, Ehlers, Georg, McQueeney, Robert J., and Vaknin, David. Thu . "Hybrid excitations due to crystal field, spin-orbit coupling, and spin waves in LiFePO4". United States. doi:10.1103/PhysRevB.95.104409. https://www.osti.gov/servlets/purl/1355753.
@article{osti_1355753,
title = {Hybrid excitations due to crystal field, spin-orbit coupling, and spin waves in LiFePO4},
author = {Yiu, Yuen and Le, Manh Duc and Toft-Peterson, Rasmus and Ehlers, Georg and McQueeney, Robert J. and Vaknin, David},
abstractNote = {Here, we report on the spin waves and crystal field excitations in single crystal LiFePO 4 by inelastic neutron scattering over a wide range of temperatures, below and above the antiferromagnetic transition of this system. In particular, we find extra excitations below T N = 50 K that are nearly dispersionless and are most intense around magnetic zone centers. Furthermore, we show that these excitations correspond to transitions between thermally occupied excited states of Fe 2 + due to splitting of the S = 2 levels that arise from the crystal field and spin-orbit interactions. These excitations are further amplified by the highly distorted nature of the oxygen octahedron surrounding the iron atoms. Above T N , magnetic fluctuations are observed up to at least 720 K, with an additional inelastic excitation around 4 meV, which we attribute to single-ion effects, as its intensity weakens slightly at 720 K compared to 100 K, which is consistent with the calculated cross sections using a single-ion model. This theoretical analysis, using the MF-RPA model, provides both detailed spectra of the Fe d shell and estimates of the average ordered magnetic moment and T N . By applying the MF-RPA model to a number of existing spin-wave results from other Li M PO 4 ( M = Mn , Co, and Ni), we are able to obtain reasonable predictions for the moment sizes and transition temperatures.},
doi = {10.1103/PhysRevB.95.104409},
journal = {Physical Review B},
number = 10,
volume = 95,
place = {United States},
year = {2017},
month = {3}
}

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Works referenced in this record:

Electronic structure and half-metallic transport in the La 1 x Ca x MnO 3 system
journal, January 1996


Inelastic neutron scattering study of crystal field excitations of Nd 3 + in NdFeAsO
journal, December 2013


Magnetic excitations in the antiferromagnetic phase of NdCu 2
journal, December 2002

  • Rotter, M.; Kramp, S.; Loewenhaupt, M.
  • Applied Physics A: Materials Science & Processing, Vol. 74, Issue 0
  • DOI: 10.1007/s003390201358

Outline of neutron scattering formalism
journal, January 1993

  • Berk, N. F.
  • Journal of Research of the National Institute of Standards and Technology, Vol. 98, Issue 1
  • DOI: 10.6028/jres.098.002

Li Ion Diffusion Mechanisms in LiFePO 4 : An ab Initio Molecular Dynamics Study
journal, November 2011

  • Yang, Jianjun; Tse, John S.
  • The Journal of Physical Chemistry A, Vol. 115, Issue 45
  • DOI: 10.1021/jp205057d

Lithium ion conductivity in single crystal LiFePO4
journal, October 2008


Electronically conductive phospho-olivines as lithium storage electrodes
journal, September 2002

  • Chung, Sung-Yoon; Bloking, Jason T.; Chiang, Yet-Ming
  • Nature Materials, Vol. 1, Issue 2, p. 123-128
  • DOI: 10.1038/nmat732

Using McPhase to calculate magnetic phase diagrams of rare earth compounds
journal, May 2004


Magnetic Structures of the Triphylite LiFePO 4 and of Its Delithiated Form FePO 4
journal, October 2003

  • Rousse, G.; Rodriguez-Carvajal, J.; Patoux, S.
  • Chemistry of Materials, Vol. 15, Issue 21
  • DOI: 10.1021/cm0300462

Magnetic phase diagram of magnetoelectric LiMnPO 4
journal, June 2012


Weakly coupled antiferromagnetic planes in single-crystal LiCoPO 4
journal, May 2002


Experimental visualization of lithium diffusion in LixFePO4
journal, August 2008

  • Nishimura, Shin-ichi; Kobayashi, Genki; Ohoyama, Kenji
  • Nature Materials, Vol. 7, Issue 9
  • DOI: 10.1038/nmat2251

Field-induced magnetic phases and electric polarization in LiNiPO 4
journal, March 2009

  • Jensen, Thomas Bagger Stibius; Christensen, Niels Bech; Kenzelmann, Michel
  • Physical Review B, Vol. 79, Issue 9
  • DOI: 10.1103/PhysRevB.79.092412

Magnetic properties of lithium intercalation compounds
journal, April 2006


Anomalous magnetic structure and spin dynamics in magnetoelectric LiFePO 4
journal, July 2015

  • Toft-Petersen, Rasmus; Reehuis, Manfred; Jensen, Thomas B. S.
  • Physical Review B, Vol. 92, Issue 2
  • DOI: 10.1103/PhysRevB.92.024404

Search for the piezomagnetoelectric effect in LiCoPO 4
journal, November 1994


High-field magnetic phase transitions and spin excitations in magnetoelectric LiNiPO 4
journal, August 2011

  • Toft-Petersen, Rasmus; Jensen, Jens; Jensen, Thomas Bagger Stibius
  • Physical Review B, Vol. 84, Issue 5
  • DOI: 10.1103/PhysRevB.84.054408

Anisotropy in magnetic properties and electronic structure of single-crystal Li Fe P O 4
journal, February 2008


Spin-waves in antiferromagnetic single-crystal Li Fe P O 4
journal, January 2006


Dynamical matrix diagonalization for the calculation of dispersive excitations
journal, May 2012


Magnetism and its microscopic origin in iron-based high-temperature superconductors
journal, October 2012

  • Dai, Pengcheng; Hu, Jiangping; Dagotto, Elbio
  • Nature Physics, Vol. 8, Issue 10
  • DOI: 10.1038/nphys2438

Multiferroic magnetoelectric composites: Historical perspective, status, and future directions
journal, February 2008

  • Nan, Ce-Wen; Bichurin, M. I.; Dong, Shuxiang
  • Journal of Applied Physics, Vol. 103, Issue 3
  • DOI: 10.1063/1.2836410

Colossal magnetoresistance
journal, September 1997


A review of conduction phenomena in Li-ion batteries
journal, December 2010


Spin dynamics in the magnetoelectric effect compound LiCoPO 4
journal, November 2008


The linear magnetoelectric effect in LiCoPO 4 Revisited
journal, November 1994


Phospho-olivines as Positive-Electrode Materials for Rechargeable Lithium Batteries
journal, April 1997

  • Padhi, A. K.
  • Journal of The Electrochemical Society, Vol. 144, Issue 4, p. 1188-1194
  • DOI: 10.1149/1.1837571

Spin Current and Magnetoelectric Effect in Noncollinear Magnets
journal, July 2005


Antiferromagnetism in LiFePO4
journal, March 1967


The cold neutron chopper spectrometer at the Spallation Neutron Source—A review of the first 8 years of operation
journal, September 2016

  • Ehlers, G.; Podlesnyak, A. A.; Kolesnikov, A. I.
  • Review of Scientific Instruments, Vol. 87, Issue 9
  • DOI: 10.1063/1.4962024

A spectacularly reactive cathode
journal, November 2003


Horace : Software for the analysis of data from single crystal spectroscopy experiments at time-of-flight neutron instruments
journal, October 2016

  • Ewings, R. A.; Buts, A.; Le, M. D.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 834
  • DOI: 10.1016/j.nima.2016.07.036

The puzzle of high temperature superconductivity in layered iron pnictides and chalcogenides
journal, October 2010


Spin-orbit coupling in the first and second transition series
journal, January 1961