Magnetic properties of the one-dimensional Ca3Co2O6

Aasland, S.; Fjellvåg, Helmer; Hauback, Bjørn C.

doi:10.1016/s0038-1098(96)00531-5

Cited by 245 publications

(291 citation statements)

References 5 publications

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“…Among spin-chain systems, the compound, Ca 3 Co 2 O 6 [Ref 1,2], crystallizing in a K 4 CdCl 6 -derived rhombohedral structure, has attracted a lot of attention theoretically as well as experimentally in recent years [see, for instance, references 3-13, and articles cited therein]. This is primarily associated with the intrinsic frustration of the magnetic coupling arising from the triangular arrangement of antiferromagnetically coupled ferromagnetic chains.…”

Section: Introductionmentioning

confidence: 99%

Negative chemical pressure effects induced by Y substitution for Ca on the ‘exotic’ magnetic behavior of the spin-chain compound, Ca3Co2O6

Rayaprol

Sampathkumaran

2005

Pramana - J Phys

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The magnetic behavior of a solid solution, Ca 3-x Y x Co 2 O 6 , based on an 'exotic' spin-chain compound, Ca 3 Co 2 O 6 , crystallizing in K 4 CdCl 6 -derived rhombohedral structure is investigated. Among the compositions investigated (x= 0.0, 0.3, 0.5, 0.75 and 1.0), single phase formation persists up to x= 0.75, with the elongation of the c-axis. The present investigations reveal that the temperature at which the 'so-called' 'partially disordered antiferromagnetic structure' sets in (which occurs at 24 K for the parent compound, x= 0.0) undergoes gradual reduction with the substitution of Y for Ca, attaining the value of about 2.2 K for the nominal x = 1.0. The trend observed in this characteristic temperature is opposite to that reported under external pressure, thereby establishing that Y substitution exerts negative chemical pressure. Anomalous steps observed in the isothermal magnetization at very low temperatures (around 2 K) for x= 0.0, which have been proposed to arise from 'quantum tunneling effects' are found to vanish by a small substitution (x = 0.3) of Y for Ca. Systematics in ac and dc magnetic susceptibility behavior with Y substitution for Ca have also been probed. We believe that the present results involving the expansion of chain length without disrupting the magnetic chain may be useful to the overall understanding of the novel magnetism of the parent compound.

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Section: Introductionmentioning

confidence: 99%

Negative chemical pressure effects induced by Y substitution for Ca on the ‘exotic’ magnetic behavior of the spin-chain compound, Ca3Co2O6

Rayaprol

Sampathkumaran

2005

Pramana - J Phys

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“…According to powder neutron diffraction data reported by Fjellvåg et al room-temperature lattice constants amount to a hex = 9.0793Å and c hex = 10.381Å [2]. Data taken at 10 K by Aasland et al resulted in a hex = 9.060Å and c hex = 10.366Å with only slight changes of the atomic positional parameters as compared to 298 K [3]. The latter data were used in the calculations.…”

Section: Introductionmentioning

confidence: 99%

Extended moment formation and magnetic ordering in the trigonal chain compound Ca3Co2O6

Eyert

Laschinger

Kopp

et al. 2004

Chemical Physics Letters

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The results of electronic structure calculations for the one-dimensional magnetic chain compound Ca 3 Co 2 O 6 are presented. The calculations are based on density functional theory and the local density approximation and used the augmented spherical wave (ASW) method. Our results allow for deeper understanding of recent experimental findings. In particular, alternation of Co 3d low-and high-spin states along the characteristic chains is related to differences in the oxygen coordination at the inequivalent cobalt sites. Strong hybridization of the d states with the O 2p states lays ground for polarization of the latter and the formation of extended localized magnetic moments centered at the high-spin sites. In contrast, strong metal-metal overlap along the chains gives rise to intrachain ferromagnetic exchange coupling of the extended moments via the d 3z 2 −r 2 orbitals of the low-spin cobalt atoms.

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“…There are two probable explanations for the decrease in A TF below 100 K. One is a conventional scenario, in which a short-range 1D F order appears below 100 K as proposed by Aasland et al [11] and probably completes below ∼40 K, because both A TF (Fig. 2) and A slow (Fig.…”

Section: Figures 4(a) -4(d)mentioning

confidence: 90%

“…It was found that Ca 3 Co 2 O 6 exhibits a transition from a paramagnetic to an antiferromagnetic state below 24 K (=T N ), [11] although the magnetic structure is not fully understood even after neutron scattering studies, probably due to the competition between the intra-chain ferromagnetic (F) and inter-chain antiferromagnetic (AF) interactions. [11,12] The valence state of the Co ions was assigned to be +3; also, the spin configuration of Co 3+ ions in the CoO 6 octahedron is the lowspin (LS) state with S=0 and in the CoO 6 prism the highspin (HS) state with S=2. [11,17,18] At lower temperatures, magnetization and 59 Co-NMR measurements suggested the existence of a ferrimagnetic transition around 10 K, [12,13,19] which, however, was not seen in the specific heat (C p ).…”

Section: Introductionmentioning

confidence: 99%

Two dimensionality in quasi-one-dimensional cobalt oxides

Sugiyama

Nozaki

Brewer

et al. 2006

Physica B: Condensed Matter

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By means of muon spin rotation and relaxation (µ + SR) techniques, we have investigated the magnetism of quasi one-dimensional (1D) cobalt oxides AEn+2Con+1O3n+3 (AE=Ca, Sr and Ba, n=1, 2, 3, 5 and ∞), in which the 1D CoO3 chain is surrounded by six equally spaced chains forming a triangular lattice in the ab-plane, using polycrystalline samples, from room temperature down to 1.8 K. For the compounds with n=1 -5, transverse field µ + SR experiments showed the existence of a magnetic transition below ∼100 K. The onset temperature of the transition (T on c ) was found to decrease with n; from 100 K for n=1 to 60 K for n=5. A damped muon spin oscillation was observed only in the sample with n=1 (Ca3Co2O6), whereas only a fast relaxation obtained even at 1.8 K in the other three samples. In combination with the results of susceptibility measurements, this indicates that a two-dimensional short-range antiferromagnetic (AF) order appears below T on c for all compounds with n=1 -5; but quasi-static long-range AF order formed only in Ca3Co2O6 , below 25 K. For BaCoO3 (n=∞), as T decreased from 300 K, 1D ferromagnetic (F) order appeared below 53 K, and a sharp 2D AF transition occurred at 15 K.

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Magnetic properties of the one-dimensional Ca3Co2O6

Cited by 245 publications

References 5 publications

Negative chemical pressure effects induced by Y substitution for Ca on the ‘exotic’ magnetic behavior of the spin-chain compound, Ca3Co2O6

Negative chemical pressure effects induced by Y substitution for Ca on the ‘exotic’ magnetic behavior of the spin-chain compound, Ca3Co2O6

Extended moment formation and magnetic ordering in the trigonal chain compound Ca3Co2O6

Two dimensionality in quasi-one-dimensional cobalt oxides

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