Orbital Order and Spin Relaxation in La0.95Sr0.05MnO3

We analyze the temperature and angular dependence of the paramagnetic-resonance linewidth of La 0.95 Sr 0.05 MnO 3. The observed anisotropy can be well described by the crystal field contributions originated by the Jahn–Teller distortion. The critical behavior of the linewidth at the Jahn–Teller transition is found to be directly related with the orbital order.

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Phase Transitions and Spin Relaxation in La0.95Sr0.05MnO3

Modern Physics Letters B ◽

10.1142/s0217984903005482 ◽

2003 ◽

Vol 17 (10n12) ◽

pp. 459-467 ◽

Cited By ~ 8

Author(s):

B. I. Kochelaev ◽

E. Shilova ◽

J. Deisenhofer ◽

H.-A. Krug von Nidda ◽

A. Loidl ◽

...

Keyword(s):

Phase Transitions ◽

Model Calculation ◽

Crystal Field ◽

Spin Relaxation ◽

Paramagnetic Resonance ◽

Resonance Linewidth ◽

Teller Transition ◽

Jahn Teller

We present a model calculation of the paramagnetic-resonance linewidth in La 0.95 Sr 0.05 MnO 3. Both the temperature and the angular dependencies can be described by contributions from the crystal field due to the cooperative Jahn–Teller transition.

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Origin of Jahn-Teller Distortion and Orbital Order inLaMnO3

Physical Review Letters ◽

10.1103/physrevlett.104.086402 ◽

2010 ◽

Vol 104 (8) ◽

Cited By ~ 85

Author(s):

Eva Pavarini ◽

Erik Koch

Keyword(s):

Orbital Order ◽

Teller Distortion ◽

Jahn Teller ◽

Jahn Teller Distortion

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Quality of Bulk CdTe Substrates and its Relation to Intrinsic Defects

MRS Proceedings ◽

10.1557/proc-299-185 ◽

1994 ◽

Vol 299 ◽

Author(s):

B. K. Meyer ◽

D. M. Hofmann ◽

W. Stadler ◽

P. Emanuelsson ◽

P. Omling ◽

...

Keyword(s):

Negative Charge ◽

Acceptor Level ◽

Dangling Bond ◽

Epr Spectrum ◽

Paramagnetic Resonance ◽

Teller Distortion ◽

Jahn Teller ◽

Electron Paramagnetic ◽

Jahn Teller Distortion

AbstractBoth the cadmium vacancy (Vcd) and the tellurium vacancy (VTe) in CdTe are identified by means of electron paramagnetic resonance (EPR). The Vcd is a double acceptor and the EPR spectrum is observed in its single negative charge state. The symmetry is found to be trigonal, which can be explained in a model in which the hole occupies a dangling bond t2 orbital and the orbital degeneracy is removed by a static Jahn-Teller distortion. The hyperfine interaction shows that the hole is localised on one of the four Te neighbours. The EPR spectrum of VTe+ reveals cubic (unperturbed) symmetry and the hyperfine structure shows that the unpaired electron is equally spread over the four Cd neighboursPhoto-EPR measurements locate the 0/+ state of VTe at Ev + 0.2 eV and the 2-/- acceptor level of VCd to be situated less than 0.47 eV above the valence band.

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Magnetic structures and anisotropic excitations in Tb2Ti2O7spin liquid

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s2053273314084563 ◽

2014 ◽

Vol 70 (a1) ◽

pp. C1543-C1543

Author(s):

Isabelle Mirebeau ◽

Sylvain Petit ◽

Julien Robert ◽

Solene Guitteny ◽

Arsen Gukasov ◽

...

Keyword(s):

Crystal Field ◽

Ground State ◽

Mean Field ◽

Spin Liquid ◽

Singlet Ground State ◽

Field Calculation ◽

Teller Distortion ◽

Classical Spin ◽

Jahn Teller ◽

Jahn Teller Distortion

Geometrical frustration in the pyrochlore lattice of corner sharing tetrahedra yields exotic short range ordered ground states known as spin liquids or spin ices. Among them, Tb2Ti2O7 spin liquid (also called quantum spin ice) remains the most mysterious, in spite of 15 years of intense investigation. Our recent single crystal experiments using neutron diffraction and inelastic scattering down to 50 mK yield new insight on this question. By applying a high magnetic field along a [111] anisotropy axis [1], the Tb moments reorient gradually without showing the magnetization plateau observed in classical spin ices. Quantitative comparison with mean field calculation supports a dynamical symmetry breaking akin to a dynamic Jahn-Teller distortion, preserving the overall cubic symmetry. In the non-Kramers Tb ion this induce a quantum mixing of the wave-functions of the ground state crystal field doublet enabling the formation of a spin liquid, viewed as a non-magnetic two-singlet ground state in this mean-field picture [2]. The spin lattice coupling also shows up in the spin fluctuations in zero field [3]. Dispersive excitations emerge from pinch-points in the reciprocal space, with anisotropic spectral weight. This is the first evidence of them in a disordered ground state. They reveal the breaking of some conservation law ruling the relative orientations of the fluctuating magnetic moments in a given tetrahedron, as for the monopole excitations in classical spin ices. The algebraic character of the correlations shows that Tb2Ti2O7 ground state is akin to a Coulomb phase. Finally, the first excited crystal field level and an acoustic phonon mode interact, repelling each other. The whole results show that the magnetoelastic coupling is a key feature to understand the surprising spin liquid ground state. They call for an interaction between quadrupolar moments, whose Jahn-Teller distortion is the first (single site) approximation.

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Electron paramagnetic resonance studies of Cu 2+ ions in KZnClSO 4 ·3H 2 O: an observation of Jahn–Teller distortion

Journal of Physics and Chemistry of Solids ◽

10.1016/s0022-3697(99)00420-5 ◽

2000 ◽

Vol 61 (8) ◽

pp. 1209-1215 ◽

Cited By ~ 39

Author(s):

K.V. Narasimhulu ◽

C.S. Sunandana ◽

J.L. Rao

Keyword(s):

Electron Paramagnetic Resonance ◽

Paramagnetic Resonance ◽

Teller Distortion ◽

Jahn Teller ◽

Electron Paramagnetic ◽

Jahn Teller Distortion

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Structure-Property Relations in xCuO-(1-x)As2O3-0.7B2O3 (0.01≤x≤0.05) Glasses by Magnetic Susceptibility Measurements, IR and EPR Spectroscopy

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.111.103 ◽

2006 ◽

Vol 111 ◽

pp. 103-106

Author(s):

B.B. Das ◽

A. Gopinath

Keyword(s):

Magnetic Susceptibility ◽

Structure Property ◽

X Ray Diffraction ◽

Paramagnetic Resonance ◽

Teller Distortion ◽

Property Relations ◽

Structure Sensitive ◽

Jahn Teller ◽

Linear Fit ◽

Jahn Teller Distortion

Studies on xCuO-(1-x)As2O3-0.7B2O3(0.01≤x≤0.05) (G1-G5: x = 0.01, 0.02, 0.03, 0.04, 0.05) glasses were done using varieties of structure sensitive techniques. The powder X-ray diffraction (XRD) studies show the formation of glasses in the composition. The IR spectral results show the presence of Cu-O bond, planar [BO3/2] and [BO3 -n](n=1, 2, 3) units and tetrahedral {BO4/2]- units. The magnetic susceptibility results show Curie-Weiss behaviour in the range 4.2-400 K. The calculated values of the exchange integral from the Weiss constant obtained form the linear fit of the Curie-Weiss law are found to be in the range 5.22-29.50 meV. From the trend of the gmatrices of gơ>g⊥>ge (ge =2.0023) obtained from electron paramagnetic resonance (EPR) lineshapes simulation we conclude that the paramagnetic site in these glasses is Cu2+(3d9) which is in a tetragonally elongated octahedron [O1/2-CuO4/2-O1/2] exhibiting Jahn-Teller distortion having D4h symmetry with orbital singlet 3dx2-y2 (2B1g) as the ground state.

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Quality of Bulk Cdte Substrates and Its Relation to Intrinsic Defects

MRS Proceedings ◽

10.1557/proc-302-433 ◽

1993 ◽

Vol 302 ◽

Cited By ~ 3

Author(s):

B. K. Meyer ◽

D. M. Hofmann ◽

W. Stadler ◽

P. Emanuelsson ◽

P. Omling ◽

...

Keyword(s):

Negative Charge ◽

Acceptor Level ◽

Dangling Bond ◽

Epr Spectrum ◽

Paramagnetic Resonance ◽

Teller Distortion ◽

Jahn Teller ◽

Electron Paramagnetic ◽

Jahn Teller Distortion

ABSTRACTBoth the cadmium vacancy (Vcd) and the tellurium vacancy (VTe) in CdTe are identified by means of electron paramagnetic resonance (EPR). The VCd is a double acceptor and the EPR spectrum is observed in its single negative charge state. The symmetry is found to be trigonal, which can be explained in a model in which the hole occupies a dangling bond t2 orbital and the orbital degeneracy is removed by a static Jahn-Teller distortion. The hyperfine interaction shows that the hole is localised on one of the four Te neighbours. The EPR spectrum of VTe+ reveals cubic (unperturbed) symmetry and the hyperfine structure shows that the unpaired electron is equally spread over the four Cd neighbours.Photo-EPR measurements locate the 0/+ state of VTe at Ev + 0.2 eV and the 2−/− acceptor level of VCd to be situated less than 0.47 eV above the valence band.

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The Interplay of Open-Shell Spin-Coupling and Jahn-Teller Distortion in Benzene Radical Cation Probed by X-ray Spectroscopy

10.26434/chemrxiv.12799922.v2 ◽

2020 ◽

Author(s):

Marta L. Vidal ◽

Michael Epshtein ◽

Valeriu Scutelnic ◽

Zheyue Yang ◽

Tian Xue ◽

...

Keyword(s):

High Harmonic ◽

Open Shell ◽

Spin Coupling ◽

High Symmetry ◽

Teller Distortion ◽

Spectral Window ◽

X Ray ◽

Jahn Teller ◽

X Ray Absorption ◽

Jahn Teller Distortion

We report a theoretical investigation and elucidation of the x-ray absorption spectra of neutral benzene and of the benzene cation. The generation of the cation by multiphoton ultraviolet (UV) ionization as well as the measurement of the carbon K-edge spectra of both species using a table-top high-harmonic generation (HHG) source are described in the companion experimental paper [M. Epshtein et al., J. Phys. Chem. A., submitted. Available on ChemRxiv]. We show that the 1sC -> pi transition serves as a sensitive signature of the transient cation formation, as it occurs outside of the spectral window of the parent neutral species. Moreover, the presence of the unpaired (spectator) electron in the pi-subshell of the cation and the high symmetry of the system result in significant differences relative to neutral benzene in the spectral features associated with the 1sC ->pi* transitions. High-level calculations using equation-of-motion coupled-cluster theory provide the interpretation of the experimental spectra and insight into the electronic structure of benzene and its cation. The prominent split structure of the 1sC -> pi* band of the cation is attributed to the interplay between the coupling of the core -> pi* excitation with the unpaired electron in the pi-subshell and the Jahn-Teller distortion. The calculations attribute most of the splitting (~1-1.2 eV) to the spin coupling, which is visible already at the Franck-Condon structure, and estimate the additional splitting due to structural relaxation to be around ~0.1-0.2 eV. These results suggest that x-ray absorption with increased resolution might be able to disentangle electronic and structural aspects of the Jahn-Teller effect in benzene cation.

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Jahn-Teller Effect in Hexahydroxocuprate(II) Complexes

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19951429 ◽

1995 ◽

Vol 60 (9) ◽

pp. 1429-1434

Author(s):

Martin Breza

Keyword(s):

Hydrogen Bonding ◽

Quantum Chemical ◽

Potential Surface ◽

Hydroxyl Group ◽

Chemical Calculation ◽

Teller Distortion ◽

Jahn Teller ◽

Jahn Teller Effect ◽

Extremal Values ◽

Jahn Teller Distortion

Using semiempirical CNDO-UHF method the adiabatic potential surface of 2[Cu(OH)6]4- complexes is investigated. The values of vibration and vibronic constants for Eg - (a1g + eg) vibronic interaction attain extremal values for the optimal O-H distance. The Jahn-Teller distortion decreases with increasing O-H distance. The discrepancy between experimentally observed elongated bipyramid of [Cu(OH)6]4- in Ba2[Cu(OH)6] and the compressed one obtained by quantum-chemical calculation is explainable by hydrogen bonding of the axial hydroxyl group.

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