Temperature Dependence of the ESR Line Width in One-Dimensional S=1/2 Antiferromagnet CuCl2·2NC5H5

Ajiro, Yoshitami; Matsukawa, Shun-ichi; Yamada, Tetsuo; Haseda, Taiichiro

doi:10.1143/jpsj.39.259

Cited by 51 publications

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“…On the other hand, the temperature dependences of the linewidths seem to show the frequency dependence. For instance, the linewidth observed at 160 GHz decreases as the temperature decreases and starts to increase below around 30 K while the linewidth observed at 315 GHz is almost constant at high temperature and it starts to increase below 30 K. The overall feature resembles the temperature dependence of linewidth in the case of one dimensional antiferromagnet discussed by Ajiro et al 24) From the standard ESR theory, 25) the linewidth is related to the spin correlation function, and the linewidth is expected to increase as the spin correlation length increases irrespective of the dimensionality. Therefore, the increase of linewidth below 30 K may be also related to the development of short range order in the system.…”

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confidence: 54%

High-Field ESR Measurements of S=1/2 Kagome Lattice Antiferromagnet BaCu₃V₂O₈(OH)₂

et al. 2010

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High-field electron spin resonance (ESR) measurements have been performed on vesignieite BaCu 3 V 2 O 8 (OH) 2 , which is considered as a nearly ideal model substance of S ¼ 1=2 kagome antiferromagnet, in the temperature region from 1.9 to 265 K. The frequency region is from 60 to 360 GHz and the applied pulsed magnetic field is up to 16 T. Observed g-value and linewidth show the increase below 20 K, which suggest the development of the short range order. Moreover, a gapless spin liquid ground state is suggested from the frequency-field relation at 1.9 K.KEYWORDS: high-field ESR, kagome lattice, frustration, vesignieite, spin dynamics DOI: 10.1143/JPSJ.79.023708Highly frustrated magnetism has attracted much attention recently. Especially S ¼ 1=2 kagome lattice antiferromagnet (KAFM) is very important because it is considered to have stronger geometrical frustration than the well studied triangular lattice antiferromagnet. 1) Therefore, the ground state of S ¼ 1=2 KAFM has attracted much interest, but the theoretical studies about its ground state are still controversial. The exact diagonalization studies suggest a nonmagnetic spin liquid state with a small spin gap of the order of J=20, where J is the nearest-neighbor exchange interaction. 2)On the other hand, the other numerical calculation studies suggest the gapless ground state.3) Therefore, the experimental studies using the model substance of S ¼ 1=2 KAFM are really required, but a few model substances are known at present.Suggested model substances of S ¼ 1=2 KAFM at present are Cu 2þ minerals, herbertsmithite ZnCu 3 (OH) 6 Cl 2 , 4) vol-6) Herbertsmithite has a rhombohedral structure with the space group R " 3 3m, and is named ''structurally perfect kagome compound'' 4) because of the ideal kagome geometry of Cu 2þ ions. Although the strong antiferromagnetic exchange interaction is expected in herbertsmithite from the large negative Weiss temperature ¼ À300 K, 7) no long range order is observed down to 50 mK from the specific heat measurement 8) suggesting the existence of strong frustration in the system. However, the neutron diffraction measurement suggested that about 10% of the Cu 2þ sites in the kagome plane are substituted by Zn 2þ ions, 9) which is also supported by the NMR measurement.10)The divergent magnetic susceptibility toward T ¼ 0 observed in herbertsmithite 4) may be related to the existence of the impurity spins caused by these substitutions. On the other hand, no such substitution of Cu 2þ sites in the kagome plane is expected in the model substance volborthite because a mutual exchange between Cu 2þ and V 5þ ions is unfavorable in terms of the ionic radius and the Madelung energy. The existence of the strong frustration is suggested because the magnetic susceptibility shows no long range order down to 60 mK, but exhibits a tiny spin glass transition at 1.1 K in spite of the large negative Weiss temperature ¼ À115 K. 11,12) The magnetic susceptibility shows a broad maximum at 21 K and it shows a gapless behavior suggested by a large fin...

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High-Field ESR Measurements of S=1/2 Kagome Lattice Antiferromagnet BaCu₃V₂O₈(OH)₂

et al. 2010

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“…2. The linewidths of CHpC decrease as the temperature is decreased in high-temperature region but start to increase below 8 K. This behavior of the linewidth is similar with that observed in one-dimensional S = 1/2 antiferromagnet CuC1 2 2NC5H5 [15]. Although CHpC is not a onedimensional antiferromagnet, the observed anisotropic g-shifts and the increase of linewidth below 8 K resemble the behaviors in typical one-dimensional antiferromagnets and may suggest the formation of short-range order below 8 K in CHpC.…”

Section: Introductionsupporting

confidence: 81%

“…3. The linewidth decreases as the temperature is decreased in the high-temperature region, but it starts to increase below around 113 K. This behavior resembles the temperature dependence of a one-dimensional antiferromagnet [15]. 113 K corresponds to the temperature of the maximum magnetic susceptibility [9].…”

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confidence: 72%

Submillimeter-wave ESR measurements of low-dimensional quantum spin systems

et al. 2000

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Temperature-dependent electron spin resonance (ESR) measurements of two low-dimensional quantum spin systems, the S = 1/2 spin-ladder system Cu,(1,4-diazacycloheptane),CI 4 (Cu,(C,H 1 ,N 2)2Cl4 ) and the gapless S = I bond-alternating one-dimensional antiferromagnet trans-Ni(333-tet)(N 3 )(CIO4), have been performed. X-band electron spin resonance (ESR) measurements of single-crystal Cu,(C5 H 12 N 2 ) 2 Cl4 show the increase of linewidth and anisotropic g-shifts below 8 K similar to those known for one-dimensional antiferromagnet. On the other hand, Ni(333-tet)(N 3)(C10 4) has broad linewidth and ESR has been observed for the first time by our high-field ESR. Its linewidth increases as the temperature is decreased, while the g-shift seems to be isotropic and the g-value decreases as the temperature is decreased. This g-shift can be connected to the quantum fluctuation of the system.

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“…3(a). Although the linewidth of a typical one-dimensional antiferromagnet increases below the short-range order temperature, which corresponds to the maximum of the magnetic susceptibility, 19) the linewidths of Cu 3 (CO 3 ) 2 (OH) 2 tend to decrease at low temperature for all directions. It should be considered theoretically whether the decrease in linewidth reflects the dynamical properties of the diamond chain.…”

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High Field ESR Study of theS=1/2 Diamond-Chain Substance Cu₃(CO₃)₂(OH)₂up to the Magnetization Plateau Region

et al. 2003

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High field ESR measurements of Cu 3 (CO 3 ) 2 (OH) 2 have been performed in the frequency region from 50 to 900 GHz and in the temperature region from 1.8 to 265 K using the pulsed magnetic field up to 36 T. The large g-shifts below 23 K and the characteristic temperature dependence of the linewidth are discussed in connection with the two maxima of magnetic susceptibility observed at 5 and 23 K. Our ESR results together with the magnetization and theoretical results suggest that the ground state of the system is in the spin fluid (SF) phase at low field and low temperature. From the frequency-field dependence measurements at 1.8 K, the direct transition, which is closely related to the magnetization plateau from 16 to 26 T at 1.5 K, is observed for the first time. The observed frequency-field diagram suggests that the exchange interaction in the dimer is estimated to be about 50 K (1057 GHz). Recently, the study of quantum spin systems with competing interactions, that is, frustration and quantum fluctuation, has attracted great interest. The diamond chain system, as shown in Fig. 1(a), is one of such systems, and it has attracted much theoretical interest, particularly after the suggestion by Ishii et al. that Cu 3 Cl 6 (H 2 O) 2 Á2H 8 C 4 SO 2 may be the model substance for the S ¼ 1=2 distorted diamond chain with the spin gap.1) Takano et al. studied the S ¼ 1=2 diamond chain model in the case of J 1 ¼ J 3 , and showed that the ground state is in the ferrimagnetic (FRI), tetramer-dimer (TD) and dimer-monomer (DM) phases for J 2 =J 1 < 0:909, 0:909 < J 2 =J 1 < 2 and 2 < J 2 =J 1 , respectively.2) It was extended to the S ¼ 1=2 distorted diamond chain model with J 1 , J 2 and J 3 , as shown in Fig. 1(a) by Okamoto et al. and Tonegawa et al., and the ground state phase diagram in the case of H ¼ 0, composed of ferrimagnetic (FRI), dimerized (D) and spin fluid (SF) phases as schematically shown in Fig. 1(b), were determined.3,4) It turned out that the TD and DM states were special cases of the twofold degenerate D and SF states, respectively. Tonegawa et al. also studied the magnetization curve numerically. 4,5) However, it turned out recently that the compound assumed to be Cu 3 Cl 6 -(H 2 O) 2 Á2H 8 C 4 SO 2 was actually Cu 2 Cl 4 Á2H 8 C 4 SO 2 which can be described by the S ¼ 1=2 double-spin chain model. 6)Therefore, the model substance for the S ¼ 1=2 distorted diamond chain is desired strongly from the experimental point of view.Recently, Kikuchi et al. proposed that Cu 3 (CO 3 ) 2 (OH) 2 might be the first model substance for the S ¼ 1=2 diamond chain. 7) Cu 3 (CO 3 ) 2 (OH) 2 is a well-known natural mineral azurite, which has a dark blue color, and it often contains the natural mineral malachite Cu 2 (OH) 2 (CO 3 ), which has a light green color. However, little was known about the magnetic properties of Cu 3 (CO 3 ) 2 (OH) 2 previously, except for the antiferromagnetic order at T N ¼ 1:9 K from the NMR and magnetic susceptibility measurements 8,9) in the restricted low-temperature region between 1.55...

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Temperature Dependence of the ESR Line Width in One-Dimensional S=1/2 Antiferromagnet CuCl₂·2NC₅H₅

Cited by 51 publications

References 4 publications

High-Field ESR Measurements of S=1/2 Kagome Lattice Antiferromagnet BaCu₃V₂O₈(OH)₂

High-Field ESR Measurements of S=1/2 Kagome Lattice Antiferromagnet BaCu₃V₂O₈(OH)₂

Submillimeter-wave ESR measurements of low-dimensional quantum spin systems

High Field ESR Study of theS=1/2 Diamond-Chain Substance Cu₃(CO₃)₂(OH)₂up to the Magnetization Plateau Region

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Temperature Dependence of the ESR Line Width in One-Dimensional S=1/2 Antiferromagnet CuCl2·2NC5H5

Cited by 51 publications

References 4 publications

High-Field ESR Measurements of S=1/2 Kagome Lattice Antiferromagnet BaCu3V2O8(OH)2

High-Field ESR Measurements of S=1/2 Kagome Lattice Antiferromagnet BaCu3V2O8(OH)2

Submillimeter-wave ESR measurements of low-dimensional quantum spin systems

High Field ESR Study of theS=1/2 Diamond-Chain Substance Cu3(CO3)2(OH)2up to the Magnetization Plateau Region

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Temperature Dependence of the ESR Line Width in One-Dimensional S=1/2 Antiferromagnet CuCl₂·2NC₅H₅

High-Field ESR Measurements of S=1/2 Kagome Lattice Antiferromagnet BaCu₃V₂O₈(OH)₂

High-Field ESR Measurements of S=1/2 Kagome Lattice Antiferromagnet BaCu₃V₂O₈(OH)₂

High Field ESR Study of theS=1/2 Diamond-Chain Substance Cu₃(CO₃)₂(OH)₂up to the Magnetization Plateau Region