Observation of lattice dimerization in spin-singlet low temperature phase of NaTiSi2O6

Ninomiya, Emi

doi:10.1016/s0921-4526(02)02559-0

Cited by 21 publications

(4 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, the behavior of the magnetic instability at Tϭ210 K could, in principle, be of the SP type. This is further supported by an x-ray study, 11 which shows existence of a large alternation of the Ti-Ti distance at temperatures below T c . But already the hightemperature magnetic susceptibility data does not support such a SP scenario, since the phase transition occurs at a temperature that is higher then the maximum point of the Bonner-Fisher curve, 12 which implies that the transition cannot solely be driven by magnetic fluctuations.…”

supporting

confidence: 54%

See 1 more Smart Citation

Orbital dimerization inNaTiSi2O6:An orbital analogue of the spin-Peierls phase transition

et al. 2004

View full text Add to dashboard Cite

We measure the Raman scattering spectra of NaTiSi 2 O 6 , analyze the vibrational properties, and study the origin of the phase transition in this compound. In this quasi-one-dimensional Sϭ1/2 system we observe anomalous high-temperature phonon broadenings, and large changes of the phonon energies and line-widths across the phase transition temperature of 210 K. These results, combined with theoretical considerations, indicate that the phonon anomalies originate from an orbital order-disorder type of phase transition. We find that the high temperature dynamical Jahn-Teller phase of NaTiSi 2 O 6 exhibits a spontaneous breaking of translational symmetry into a dimerized, Jahn-Teller distorted, orbital ordered state under the formation of spin valence bonds.

show abstract

supporting

confidence: 54%

“…This symmetry change requires the translation symmetry breaking of the TiO 6 chain which is in agreement with pre- liminary x-ray diffraction and neutron scattering data. 11 Second, we show in detail the temperature dependence of the structure around 970 cm Ϫ1 ͓Figs. 3͑c͒ and 3͑d͔͒.…”

mentioning

confidence: 99%

Orbital dimerization inNaTiSi2O6:An orbital analogue of the spin-Peierls phase transition

et al. 2004

View full text Add to dashboard Cite

show abstract

“…The compounds show a phase transition at T c ≃ 200K where the magnetic susceptibility suddenly drops and the lattice structure is dimerized along the 1D zig-zag chains. 6), 7) The temperature dependence of the magnetic susceptibility as well as the estimate of the spin gap compared to T c suggests that the transition cannot be understood by the usual spin-Peierls mechanism. 6) We have considered the mechanism of this peculiar transition by taking account of the twofold orbital degeneracy explicitly.…”

Section: Titanium Pyroxenesmentioning

confidence: 99%

Interplay among Spin, Orbital and Lattice Degrees of Freedom int_2gElectron Systems with Edge-Sharing Network of Octahedra

Motome¹,

Tsunetsugu²,

Hikihara³

et al. 2005

Prog. Theor. Phys. Suppl.

View full text Add to dashboard Cite

Transition metal oxides whose lattice structure has edge-sharing network of octahedra constitute a diverse group of intriguing materials besides compounds with corner-sharing octahedra such as perovskites. We present a theoretical investigation of the interplay among spin, orbital and lattice degrees of freedom in these materials. We focus on t2g electron systems where a keen competition among those degrees of freedom is expected to emerge under a relatively weak Jahn-Teller coupling. We study the interplay between spin and orbital degrees of freedom in vanadium spinels and titanium pyroxenes. We clarify the important role of the strong anisotropy in the orbital interactions due to the edge-sharing geometry. We also discuss the interplay between spin and lattice in chromium spinels focusing on the magnetization process under the external magnetic field. §1. IntroductionTransition metal oxides, in many cases, consist of the basic unit of octahedron where a metal is surrounded by six oxygens. One of the famous families is the perovskite such as high-T c cuprates and CMR manganites, in which octahedra form two-dimensional (2D) or three-dimensional (3D) network by sharing oxygens at their corner. Another typical geometry is the edge-sharing network of octahedra. An old but still intriguing example is the spinel in which octahedra form 3D edge-sharing network. A 2D example is found in the sodium cobaltite which has a triangular lattice of Co cations. There, a large thermoelectric effect or superconductivity is recently attracting much interest.In this paper, we present our recent theoretical efforts to understand remarkable properties in several edge-sharing materials with focusing on a keen competition among spin, orbital and lattice degrees of freedom. In the octahedral coordinate, the fivefold energy levels of d electrons of transition metals split into lower threefold t 2g levels and higher twofold e g levels. Here, we consider the systems in which electrons in the t 2g levels play a central role. In the t 2g electron systems, it is known that the Jahn-Teller interaction is rather weak compared to the e g systems.

show abstract

“…In the materials science the chemical composition of the synthetic analogs of pyroxenes is more limited and the field is not well explored. Due to the chain-like structural arrangement of the transition metal cations the synthetic pyroxens are attracting a considerable interest due their quasi-one-dimensional magnetic and multiferroic properties [6][7][8][9][10][11][12]. However, the preparation synthetic pyroxens is often marked by complex high-temperature and/or highpressure conditions.…”

Section: Introductionmentioning

confidence: 99%

Mild hydrothermal synthesis and structural characterization of nanosized pyroxene-type NaVSi2O6

Ferdov

2015

Ceramics International

View full text Add to dashboard Cite

Observation of lattice dimerization in spin-singlet low temperature phase of NaTiSi2O6

Cited by 21 publications

References 1 publication

Orbital dimerization inNaTiSi2O6:An orbital analogue of the spin-Peierls phase transition

Orbital dimerization inNaTiSi2O6:An orbital analogue of the spin-Peierls phase transition

Interplay among Spin, Orbital and Lattice Degrees of Freedom int_2gElectron Systems with Edge-Sharing Network of Octahedra

Mild hydrothermal synthesis and structural characterization of nanosized pyroxene-type NaVSi2O6

Contact Info

Product

Resources

About

Observation of lattice dimerization in spin-singlet low temperature phase of NaTiSi2O6

Cited by 21 publications

References 1 publication

Orbital dimerization inNaTiSi2O6:An orbital analogue of the spin-Peierls phase transition

Orbital dimerization inNaTiSi2O6:An orbital analogue of the spin-Peierls phase transition

Interplay among Spin, Orbital and Lattice Degrees of Freedom int2gElectron Systems with Edge-Sharing Network of Octahedra

Mild hydrothermal synthesis and structural characterization of nanosized pyroxene-type NaVSi2O6

Contact Info

Product

Resources

About

Interplay among Spin, Orbital and Lattice Degrees of Freedom int_2gElectron Systems with Edge-Sharing Network of Octahedra