Coupling of Li motion and structural distortions in olivine LiMnPO<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mrow /><mml:mn>4</mml:mn></mml:msub></mml:math>from<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mrow /><mml:mn>7</mml:mn></mml:msup></mml:math>Li and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mrow /><mml:mn>31</mml:mn></mml:msup></mml:math>P NMR

Rudisch, Christian; Grafe, H.-J.; Geck, J.; Partzsch, Sven; Zimmermann, M. v.; Wizent, N.; Klingeler, R.; Büchner, B.

doi:10.1103/physrevb.88.054303

Cited by 12 publications

(4 citation statements)

References 21 publications

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“…The Fe substitution can improve ion diffusion and electron conductivity. With the doping of Fe, Fe and Mn will build up Fe-O-Mn superexchange interaction, by this interaction, the electronics cloud moved from Fe to Mn, which reduces the Fe 3+ /Fe 2+ couple (higher voltage) and raises Mn 3+ /Mn 2+ couple (lower voltage) by 0.1 V [33][34][35]39]. The initial discharge capacities of LMP/C-1 and LMP/C-2 are 159.2 and 153.8 mA h g À1 , respectively.…”

Section: Electrochemical Propertiesmentioning

confidence: 99%

Ionothermal synthesis and electrochemical analysis of Fe doped LiMnPO4/C composites as cathode materials for lithium-ion batteries

Liu

Jin

et al. 2014

Journal of Alloys and Compounds

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Section: Electrochemical Propertiesmentioning

confidence: 99%

Ionothermal synthesis and electrochemical analysis of Fe doped LiMnPO4/C composites as cathode materials for lithium-ion batteries

Liu

Jin

et al. 2014

Journal of Alloys and Compounds

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“…In general, depending on the actual transition metal, LiM PO 4 develops long-range antiferromagnetic order at low temperatures and exhibits a large magneto-electric effect in the magnetically ordered phase [1,9,10]. The known magnetic phase diagrams of this family are rather complex, featuring incommensurate spin configurations, frustration, and usual magnetic excitations [11][12][13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

High magnetic field phase diagram and failure of the magnetic Grüneisen scaling in LiFePO4

et al. 2019

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We report the magnetic phase diagram of single-crystalline LiFePO 4 in magnetic fields up to 58 T and present a detailed study of magneto-elastic coupling by means of high-resolution capacitance dilatometry. Large anomalies at T N in the thermal expansion coefficient α imply pronounced magneto-elastic coupling. Quantitative analysis yields the magnetic Grüneisen parameter γ mag = 6.7(5) · 10 −7 mol/J. The positive hydrostatic pressure dependence dT N /dp = 1.46(11) K/GPa is dominated by uniaxial effects along the a-axis. Failure of Grüneisen scaling below ≈ 40 K, i.e., below the peak temperature in the magneto-electric coupling coefficient [1], implies several competing degrees of freedom and indicates relevance of recently observed hybrid excitations [2].A broad and strongly magnetic-field-dependent anomaly in α in this temperature regime highlight the relevance of structure changes. Upon application of magnetic fields B||b-axis, a pronounced jump in the magnetisation implies spin-reorientation at B SF = 32 T as well as a precursing phase at 29 T and T = 1.5 K. In a two-sublattice mean-field model, the saturation field B sat,b = 64(2) T enables the determination of the effective antiferromagnetic exchange interaction J af = 2.68(5) meV as well as the anisotropies D b = −0.53(4) meV and D c = 0.44(8) meV. PACS numbers:In addition to exceptionally high applicability of lithium orthophosphates [3][4][5] for electrochemical energy storage in Li-ion batteries, competing magnetic interactions, magnetic anisotropy and coupling of spin and electric degrees of freedom yield complex magnetic behaviour in LiM PO 4 (M = Mn, Fe, Co, Ni). The rich resulting physics is, e.g., demonstrated by ferrotoroidicity in LiCoPO 4 and LiNiPO 4 [6-8]. In general, depending on the actual transition metal, LiM PO 4 develops long-range antiferromagnetic order at low temperatures and exhibits a large magneto-electric effect in the magnetically ordered phase [1, 9, 10]. The known magnetic phase diagrams of this family are rather complex, featuring incommensurate spin configurations, frustration, and usual magnetic excitations [11-17]. Magnetic phase diagrams have been reported for all lithium orthophosphates [15-17] except for LiFePO 4 . At B = 0 T, LiFePO 4 develops long-range antiferromagnetic order of S = 2 spins of the magnetic Fe 2+ -ions below T N = 50 K [18]. The ordered moment amounts to 4.09 µ B [1, 19] and the spins are mainly directed along the crystallographic b-axis (space group P nma) [19]. Notably, the ground state features a collinear rotation of the spins towards the a-axis as well as spin canting along the c-axis with an overall rotation of the ordered moments of 1.3(1) • off the b-axis [1, 2]. The observed spin canting suggests the presence of Dzyaloshinsky-Moriya (DM) interactions which may account for the magneto-electric coupling in LiFePO 4 . In particular, as spin canting is not compatible with P nma symmetry, a lower crystal symmetry might appear below T N [ 1,20]. Even in the absence of spin canting, an alternative me...

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“…7 Li and 31 P NMR measurements have been carried out using a spin-echo method in a fixed field of 7.0494 T in the temperature range of 5-400 K. Since 31 P (nuclear spin I = 1/2, γ n = 17.2356 MHz/T) does not involve electric quadrupole effects, it is an ideal probe to study magnetism and spin fluctuations in these materials. 31 P NMR spectra over most of the measured temperature range are relatively narrow and quite symmetric, in comparison with the large linewidth and strong anisotropy observed in other Li phosphates, 25,26 which allowed us to determine the Knight shift and the linewidth reliably. The spin-lattice relaxation rates T −1 1 of both 31 P and 7 Li (I = 3/2, γ n = 16.5471 MHz/T) were measured using the saturation recovery method and T 1 was obtained by fitting the relaxation of the nuclear magnetization M (t) to a single exponential function, 1 − M (t)/M (∞) = A exp(−t/T 1 ) where A is a fitting parameter.…”

Section: Sample Preparation and Experimental Detailsmentioning

confidence: 85%

Unusual spin fluctuations and magnetic frustration in olivine and non-olivine LiCoPO4detected byP31and
Baek
¹
,
Klingeler
²
,
Neef
³

et al. 2014
Phys. Rev. B

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We report 31 P and 7 Li nuclear magnetic resonance (NMR) studies in new non-olivine LiZnPO4type LiCoPO tetra 4 microcrystals, where the Co 2+ ions are tetrahedrally coordinated. Olivine LiCoPO4, which was directly transformed from LiCoPO tetra 4 by an annealing process, was also studied and compared. The uniform bulk magnetic susceptibility and the 31 P Knight shift obey the Curie-Weiss law for both materials with a high spin Co 2+ (3d 7 , S = 3/2), but the Weiss temperature Θ and the effective magnetic moment µ eff are considerably smaller in LiCoPO tetra 4 . The spin-lattice relaxation rate T −1 1 reveals a quite different nature of the spin dynamics in the paramagnetic state of both materials. Our NMR results imply that strong geometrical spin frustration occurs in tetrahedrally coordinated LiCoPO4, which may lead to the incommensurate magnetic ordering.

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Coupling of Li motion and structural distortions in olivine LiMnPO4from7Li and31P NMR

Cited by 12 publications

References 21 publications

Ionothermal synthesis and electrochemical analysis of Fe doped LiMnPO4/C composites as cathode materials for lithium-ion batteries

Ionothermal synthesis and electrochemical analysis of Fe doped LiMnPO4/C composites as cathode materials for lithium-ion batteries

High magnetic field phase diagram and failure of the magnetic Grüneisen scaling in LiFePO4

Unusual spin fluctuations and magnetic frustration in olivine and non-olivine LiCoPO4detected byP31and
Baek
¹
,
Klingeler
²
,
Neef
³

et al. 2014
Phys. Rev. B

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Coupling of Li motion and structural distortions in olivine LiMnPO4from7Li and31P NMR

Cited by 12 publications

References 21 publications

Ionothermal synthesis and electrochemical analysis of Fe doped LiMnPO4/C composites as cathode materials for lithium-ion batteries

Ionothermal synthesis and electrochemical analysis of Fe doped LiMnPO4/C composites as cathode materials for lithium-ion batteries

High magnetic field phase diagram and failure of the magnetic Grüneisen scaling in LiFePO4

Unusual spin fluctuations and magnetic frustration in olivine and non-olivine LiCoPO4detected byP31andBaek1, Klingeler2, Neef3 et al. 2014Phys. Rev. B

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Product

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Unusual spin fluctuations and magnetic frustration in olivine and non-olivine LiCoPO4detected byP31and
Baek
¹
,
Klingeler
²
,
Neef
³

et al. 2014
Phys. Rev. B