New results on the magnetic phases of CsCuCl3 in the external field

Werner, Tomasz; Weber, Heidrun; Wosnitza, J.; Kelnberger, A; Meschke, Matthias; Schotte, U.; Stüßer, N.; Ding, Y; Winkelmann, M.

doi:10.1016/s0038-1098(96)00782-x

Cited by 14 publications

(20 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…28: the neutron-scattering intensity as a function of wavenumber is qualitatively that expected from the order parameter of the IC 2 phase. The companion article compares theory and experiment in other respects as well.…”

Section: Phase Diagram and Other Resultsmentioning

confidence: 63%

“…Phase diagrams (order of the transitions): The fields available in the high-T neutron measurements 28,31 were not sufficient to observe the C phase, nor of course the IC 1 →C and C→P transitions; the IC 1 →C transition was however observed 27 at low T , at H ≈ 18 T. In theory, all four of the other transitions in Figure 1 are first-order. IC 1 →IC 2 is strongly first-order, while the three transitions to the P state (IC 1 →P near T N , IC 2 →P and IC 1 →P at lower T ) are weakly first-order (the free energies cross with almost the same slope); the IC 1 →P transition is second-order at H = 0.…”

Section: Phase Diagram and Other Resultsmentioning

confidence: 95%

“…Classical theory cannot, however, explain any of the following: At low T , unusual behaviour occurs for fields near H = H S /3, well below the IC→C transition; structure is found in the magnetization 13 20 . At high T , a second IC phase appears and T N increases with field 28 . At low T , the structure near H S /3 seems related to changes, induced by quantum fluctuations, in the structure of the TAFM near the same field 10,11 .…”

Section: Introductionmentioning

confidence: 97%

See 2 more Smart Citations

Fluctuation-induced phase in in a transverse magnetic field: theory

Jacobs

Nikuni

1998

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

CsCuCl 3 is a quantum triangular antiferromagnet, ferromagnetically stacked, with an incommensurate (IC) structure due to a DzyaloshinskiiMoriya interaction. Because of the classical degeneracy caused by the frustration, fluctuations in CsCuCl 3 have extraordinarily large effects, such as the phase transition in longitudinal magnetic field (normal to the planes, parallel to the IC wavenumber q) and the plateau in q in transverse field (perpendicular to q). We argue that fluctuations are responsible also for the new IC phase discovered in transverse field near the Néel temperature T N , by T. Werner et al. [Solid State Commun. 102, 609 (1997)]. We develop and analyse the corresponding minimal Landau theory; the effects of fluctuations on the frustration are included phenomenologically, by means of a biquadratic term. The Landau theory gives two IC phases, one familiar from previous studies; properties of the new IC phase, which occupies a pocket of the temperature-field phase diagram near T N , agree qualitatively with those of the new phase found experimentally. 64.70.Rh, 75.10.Jm, 75.25.+z, 75.50.Ee

show abstract

Section: Phase Diagram and Other Resultsmentioning

confidence: 63%

Section: Phase Diagram and Other Resultsmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 97%

See 1 more Smart Citation

Fluctuation-induced phase in in a transverse magnetic field: theory

Jacobs

Nikuni

1998

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…22,[60][61][62][63][64][65][66][67][68][69][70] The Cu 2+ ion is Jahn-Teller active, when it is surrounded octahedrally by anions. For this reason, CsCuCl 3 undergoes a structural phase transition at T t = 423 K. For T < T t , CuCl 6 octahedra are elongated along the one of the principal axes and the elongated axes form a helix along the c-axis with a repeat length of six.…”

Section: Cscuclmentioning

confidence: 99%

Electron Spin Resonance in Triangular Antiferromagnets

et al. 2003

View full text Add to dashboard Cite

We give an overview of our studies on the electron spin resonance (ESR) in the hexagonal triangular antiferromagnets of ABX 3 type using millimeter and submillimeter waves and static and pulsed high magnetic fields. Novel ESR modes, which cannot be understood by the conventional theory of the antiferromagnetic resonance, were observed. Examples of this include that there exists the gapless excitation even for the easy-axis anisotropy. The ESR modes can be classified by the signs of the exchange interaction J 0 along the c-axis and the anisotropy. The ESR modes were calculated within the framework of the mean-field approximation using threesublattice and six-sublattice models for the ferromagnetic and antiferromagnetic J 0 interaction, respectively. The experimental results were well described by the present calculations.KEYWORDS: ESR, triangular antiferromagnet, spin wave, antiferromagnetic resonance, frustration, hexagonal ABX 3 antiferromagnet §1. IntroductionSpin waves are beautiful collective excitations in magnetic systems. From the dispersion relations, we can know the exchange interactions, the magnetic anisotropies, the dimensionality of the system and so on. Neutron inelastic scattering and electron spin resonance (ESR) are powerful tools to observe the spin waves. Neutron inelastic scattering can excite the spin waves with various wave number Q, while the ESR can excite only Q = 0 modes. However, the ESR has the much higher resolution. Furthermore, using the millimeter and submillimeter waves ESR combined with pulsed high magnetic field, can observe the evolution of spin wave energies with magnetic field in the wide field range.The antiferromagnetic resonance (AFMR) is the ESR in the antiferromagnets, in which the spin structure can be described by two sublattices. The theory of AFMR has been established many years ago, 1-10) and were confirmed experimentally in many antiferromagnets. Figure 1 illustrates the frequency versus field diagrams of the AFMR modes for the uniaxial and biaxial anisotropies. For the uniaxial easy-axis and biaxial anisotropies, there is finite zero-field gap, while no zero-field gap exists for the uniaxial easy-plane anisotropy.For triangular antiferromagnets (TAF), little was known on the ESR modes.11) This seems because there was little suitable model substance and there was no standard theory. The comprehensive studies of the ESR * E-mail address: tanaka@lee.phys.titech.ac.jp. modes in the TAF started in the late 1980's on the hexagonal antiferromagnets of ABX 3 type with the CsNiCl 3 structure. 12-14)In the hexagonal antiferromagnets of ABX 3 -type, magnetic B 2+ ions form infinite chains along the crystallographic c-axis and triangular lattices in the basal c-plane, as shown in Fig. 2. Figure 3 shows the exchange interactions in the hexagonal antiferromagnets of ABX 3 -type. The intrachain interaction J 0 is stronger than the others. Thus, the present system exhibits the one-dimensional character at high temperatures. However, they behave as TAF at low temperatures, becau...

show abstract

“…Among the group of antiferromagnets which have a hexagonal ABX 3 triangular structure, many experimental and theoretical investigations for CsCuCl 3 have been done by several authors , [1][2][3][4] due to the remarkable features of this compound. Since the Cu 2+ ion is JahnTeller active, CsCuCl 3 undergoes a structural phase transition at T t = 423 K, where Jahn-Teller distorted octahedra CuCl 6 order so that their longest axes form a helix along the c-axis with a repeatlength of six .…”

Section: §1 Introductionmentioning

confidence: 99%

Oblique triangular antiferromagnetic phase inCsCu1−xCoxCl

et al. 2001

View full text Add to dashboard Cite

The spin-1 2 stacked triangular antiferromagnet CsCu1−xCoxCl3 with 0.015 < x < 0.032 undergoes two phase transitions at zero field. The low-temperature phase is produced by the small amount of Co 2+ doping. In order to investigate the magnetic structures of the two ordered phases, the neutron elastic scattering experiments have been carried out for the sample with x ≈ 0.03. It is found that the intermediate phase is identical to the ordered phase of CsCuCl3, and that the low-temperature phase is an oblique triangular antiferromagnetic phase in which the spins form a triangular structure in a plane tilted from the basal plane. The tilting angle which is 42 • at T = 1.6 K decreases with increasing temperature, and becomes zero at TN2 = 7.2 K. An off-diagonal exchange term is proposed as the origin of the oblique phase. §1. Introduction Among the group of antiferromagnets which have a hexagonal ABX 3 triangular structure, many experimental and theoretical investigations for CsCuCl 3 have been done by several authors , 1-4) due to the remarkable features of this compound. Since the Cu 2+ ion is JahnTeller active, CsCuCl 3 undergoes a structural phase transition at T t = 423 K, where Jahn-Teller distorted octahedra CuCl 6 order so that their longest axes form a helix along the c-axis with a repeatlength of six . 5-7) The low-symmetric crystal structure produces the antisymmetric interaction of the Dzyaloshinsky-Moriya (D-M) type between the adjacent spins in the chain with the Dvector parallel to the c-direction. The exchange interactions along and between the chains are ferromagnetic and antiferromagnetic, respectively, and their values have been evaluated as J 0 /k B = 28 K and J 1 /k B = −4.9 K 8, 9) in the definition of H = − 2J ij S i · S j . The magnetic phase transition occurs at T N = 10.5 K . 10, 11) In the ordered state, spins lie in the basal plane and form the 120 • -structure, while along the c-direction, a long period (about 71 triangular layers) helical incommensurate arrangement is realized, due to the competition between the ferromagnetic interaction and the D-M interaction along the chain.Since the magnitude of spin on Cu 2+ is S = 1 2 , quantum fluctuations are important when one describes the magnetic behavior in the magnetic field . 12) Particularly, the magnetization process with a strong field often reveals quantum effects as macroscopic phenomena. Using quantum Monte Carlo calculations or spin wave theory, for the 2D triangular antiferromagnet (TAF) in the isotropic limit, it is predicted that the magnetization plateau appears at around one third of the saturation value M s . 13, 14) According to these predictions, when * Present address: Faculty of Education, Chiba University, 263-8522 Chiba, Japan.the external field H is applied parallel to the c-axis, 2D TAF undergoes a successive phase transition as shown in Fig. 1 (b) low-field coplanar, (c) collinear and (d) highfield coplanar structure in that order. In the field region where the magnetization plateau appears, the spin structure c...

show abstract

New results on the magnetic phases of CsCuCl3 in the external field

Cited by 14 publications

References 11 publications

Fluctuation-induced phase in in a transverse magnetic field: theory

Fluctuation-induced phase in in a transverse magnetic field: theory

Electron Spin Resonance in Triangular Antiferromagnets

Oblique triangular antiferromagnetic phase inCsCu1−xCoxCl

Contact Info

Product

Resources

About