Magnetic model for<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>A</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>CuP<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mrow /><mml:mn>2</mml:mn></mml:msub></mml:math>O<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mrow /><mml:mn>7</mml:mn></mml:msub></mml:math>(<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline">

Structural and magnetic properties of a quasi-one-dimensional spin-1/2 compound NaVOPO4 are explored by x-ray diffraction, magnetic susceptibility, high-field magnetization, specific heat, electron spin resonance, and 31 P nuclear magnetic resonance measurements, as well as complementary ab initio calculations. Whereas magnetic susceptibility of NaVOPO4 may be compatible with the gapless uniform spin chain model, detailed examination of the crystal structure reveals a weak alternation of the exchange couplings with the alternation ratio α 0.98 and the ensuing zero-field spin gap ∆0/kB 2.4 K directly probed by field-dependent magnetization measurements. No longrange order is observed down to 50 mK in zero field. However, applied fields above the critical field Hc1 1.6 T give rise to a magnetic ordering transition with the phase boundary TN ∝ (H − Hc1)

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“…3 K, assuming the 1D uniform spin chain model. [41] This value of J/k B matches well with the one obtained from the χ(T ) analysis.…”

Section: B Magnetizationsupporting

confidence: 86%

Bose-Einstein condensation of triplons close to the quantum critical point in the quasi-one-dimensional spin- 12 antiferromagnet NaVOPO4

et al. 2019

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“…4). For a spin-1/2 Heisenberg AFM chain, the saturation field is directly proportional to the intrachain exchange coupling as H s = 2J 1D (k B /gμ B ) [44]. Using the value of J/k B 5.6 K, the saturation field is calculated to be H s 8.34 T, which matches well with the experimental value, confirming the dominant 1D character of the compound.…”

Section: A Magnetizationsupporting

confidence: 77%

Quasi-one-dimensional magnetism in the spin- 12 antiferromagnet BaNa2Cu(VO4)2
Sebastian
¹
,
Somesh
²
,
Nandi
³

et al. 2021
Phys. Rev. B
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We report synthesis and magnetic properties of quasi-one-dimensional spin-12 Heisenberg antiferromagnetic chain compound BaNa2Cu(VO4)2. This orthovanadate has a centrosymmetric crystal structure, C2/c, where the magnetic Cu2+ ions form spin chains. These chains are arranged in layers, with the chain direction changing by 62∘ between the two successive layers. Alternatively, the spin lattice can be viewed as anisotropic triangular layers upon taking the interchain interactions into consideration. Despite this potential structural complexity, temperature-dependent magnetic susceptibility, heat capacity, electron spin resonance intensity, and nuclear magnetic resonance (NMR) shift agree well with the uniform spin-1/2 Heisenberg chain model with an intrachain coupling of J/kB≃5.6 K. The saturation field obtained from the magnetic isotherm measurement consistently reproduces the value of J/kB. Further, the 51V NMR spin-lattice relaxation rate mimics the one-dimensional character in the intermediate temperature range, whereas magnetic long-range order sets in below TN≃0.25 K. The effective interchain coupling is estimated to be J⊥/kB≃0.1 K. The theoretical estimation of exchange couplings using bandstructure calculations reciprocate our experimental findings and unambiguously establish the onedimensional character of the compound. Finally, the spin lattice of BaNa2Cu(VO4)2 is compared with the chemically similar but not isostructural compound BaAg2Cu(VO4)2.

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“…Accordingly, we employ numerical electronic structure DFT calculations allowing for a direct computation of individual exchange couplings J ij . In combination with numerical simulations of the thermodynamical properties, such calculations often provided consistent description of the macroscopic magnetic behavior based on microscopic considerations [13,29,33,62].…”

Section: Electronic Structure and Magnetic Exchange Couplingsmentioning

confidence: 99%

Interplay of magnetic sublattices in langite Cu₄(OH)₆SO₄· 2H₂O

et al. 2016

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Magnetic and crystallographic properties of the mineral langite Cu 4 (OH) 6 SO 2 4 · H 2 O are reported. Thermodynamic measurements combined with a microscopic analysis, based on density-functional bandstructure calculations, identify a quasi-two-dimensional (2D), partially frustrated spin-1/2 lattice resulting in the low Néel temperature of T 5.7 N  K. This spin lattice splits into two parts with predominant ferro-and antiferromagnetic (AFM) exchange couplings, respectively. The former, ferromagnetic (FM) part is prone to the long-range magnetic order and saturates around 12 T, where the magnetization reaches 0.5 B m /Cu. The latter, AFM part features a spin-ladder geometry and should evade long-range magnetic order. This representation is corroborated by the peculiar temperature dependence of the specific heat in the magnetically ordered state. We argue that this separation into ferro-and antiferromagnetic sublattices is generic for quantum magnets in Cu 2+ oxides that combine different flavors of structural chains built of CuO 4 units. To start from reliable structural data, the crystal structure of langite in the 100-280 K temperature range has been determined by single-crystal x-ray diffraction, and the hydrogen positions were refined computationally.chains develop incommensurate spin correlations and helical magnetic order [8,9], although few instances of FM intrachain spin order are known as well [10,11]. The helical spin arrangement observed in simple binary compounds CuCl 2 [12] and CuBr 2 [13] and in more complex materials like linarite PbCu(OH) 2 SO 4 [14], all being frustrated J J 1 2 spin chains, may trigger electric polarization induced by the magnetic order, thus leading to multiferroic behavior [15-18]. Additionally, small interactions beyond the isotropic Heisenberg model lead to an intricate magnetic phase diagram, including multipolar (three-magnon) phases, which has been studied recently [19]. However, the complex interplay of frustration and anisotropy needs further investigations on different systems as, e.g., LiCuVO 4 [20-23]. One may naturally ask what happens when two types of spin chains, those with edge-and corner-sharing geometries, are placed next to each other within one material. Spin systems comprising several magnetic OPEN ACCESS RECEIVED =. A more detailed description of the procedure can be found, e.g., in [31,54]. Alternatively, strong electron correlations are added on top of LDA by the LSDA+U method in a mean-field way and are thus included in the self-consistent procedure. This allows for calculating total exchange constants J J J ij ij ij FM AFM ( ) m = J J J 81

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Magnetic model forA2CuP2O7(

Cited by 27 publications

References 67 publications

Bose-Einstein condensation of triplons close to the quantum critical point in the quasi-one-dimensional spin- 12 antiferromagnet NaVOPO4

Bose-Einstein condensation of triplons close to the quantum critical point in the quasi-one-dimensional spin- 12 antiferromagnet NaVOPO4

Quasi-one-dimensional magnetism in the spin- 12 antiferromagnet BaNa2Cu(VO4)2
Sebastian
¹
,
Somesh
²
,
Nandi
³

et al. 2021
Phys. Rev. B
Self Cite
21
0
8
0
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Interplay of magnetic sublattices in langite Cu₄(OH)₆SO₄· 2H₂O

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Magnetic model forA2CuP2O7(

Cited by 27 publications

References 67 publications

Bose-Einstein condensation of triplons close to the quantum critical point in the quasi-one-dimensional spin- 12 antiferromagnet NaVOPO4

Bose-Einstein condensation of triplons close to the quantum critical point in the quasi-one-dimensional spin- 12 antiferromagnet NaVOPO4

Quasi-one-dimensional magnetism in the spin- 12 antiferromagnet BaNa2Cu(VO4)2Sebastian1, Somesh2, Nandi3 et al. 2021Phys. Rev. BSelf Cite21080View full textAdd to dashboardCite

Interplay of magnetic sublattices in langite Cu4(OH)6SO4· 2H2O

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Quasi-one-dimensional magnetism in the spin- 12 antiferromagnet BaNa2Cu(VO4)2
Sebastian
¹
,
Somesh
²
,
Nandi
³

et al. 2021
Phys. Rev. B
Self Cite
21
0
8
0
View full text Add to dashboard Cite

Interplay of magnetic sublattices in langite Cu₄(OH)₆SO₄· 2H₂O