Related papers: Jahn-Teller Distortion in Bimetallic Oxalates
In a metallic manganite like La(2/3)Sr(1/3)MnO(3), the substitution of Mn(+3) by Ga(+3) dilutes the ferromagnetic order and locally cancels the Jahn-Teller distortion, without heavily affecting the crystal structure. One can thus follow the…
Motivated by experimental and theoretical interest in realizing multipolar orders in $d$-orbital materials, we discuss the quantum magnetism of $J\!=\!2$ ions which can be realized in spin-orbit coupled oxides with $5d^2$ transition metal…
We present a theoretical study of a possibility of superconductivity in a three dimensional molecular conductor in which the interaction between electrons in doubly degenerate molecular orbitals and an {\em intra}molecular vibration mode is…
Based on previously computed parameters for the electron-phonon couplings and the Coulomb exchange, we compute and classify the static Jahn-Teller distortions, i.e. the minima of the lowest adiabatic potential energy surface, of C60(n+),…
We set forth the structural and magnetic properties of the frustrated spin-$5/2$ triangle lattice antiferromagnet Na$_3$Fe(PO$_4$)$_2$ examined via x-ray diffraction, magnetization, heat capacity, and neutron diffraction measurements on the…
We introduce an effective model for $e_g$ electrons to describe quasi-two-dimensional layered La$_{2-x}$Sr$_{x}$NiO$_4$ nickelates and study it using correlated wave functions on $8 \times 8 $ and $6 \times 6 $ clusters. The effective…
We report on an extended fluctuation regime in the spin dimer system Sr3Cr2O8 based on anomalies in Raman active phonons and magnetic scattering. The compound has two characteristic temperatures, TS = 275 K, related to a Jahn-Teller…
Orbital degrees of freedom mediating an interaction between spin and lattice were predicted to raise strong magnetoelectric effect, i.e. realize an efficient coupling between magnetic and ferroelectric orders. However, the effect of orbital…
Ordering and quantum fluctuations of orbital degrees of freedom are studied theoretically for LaVO$_3$ in spin-C-type antiferromagnetic state. The effective Hamiltonian for the orbital pseudospin shows strong one-dimensional anisotropy due…
The effects of the cooperative Jahn-Teller effect on the crystal structure and the stability of the charge ordered (CO) state were studied by measurements of powder X-ray diffraction, resistivity, and ultrasound for Pr1-xCaxMnO3…
We report a high-resolution neutron diffraction study of the crystal and magnetic structure of the orbitally-degenerate frustrated metallic magnet AgNiO2. At high temperatures the structure is hexagonal with a single crystallographic Ni…
Neutron diffraction measurement on the spin glass double perovskite Sr$_2$FeCoO$_6$ reveals site disorder as well as Co$^{3+}$ intermediate spin state. In addition, multiple valence states of Fe and Co are confirmed through M\"{o}ssbauer…
We argue that the Jahn-Teller theorem, if applied to 3d-ion compounds, has to be considered in the orbital+spin space. It is despite of the weakness of the intraatomic spin-orbit coupling.
We use the temperature of the structural phase transition to determine the Jahn-Teller (JT) coupling constant in the model derived for LaMnO$_3$ which includes both the superexchange between S=2 spins and the JT effect. We also investigate…
High-$T_c$ cuprates like $La_{2-x}Sr_{x}CuO_{4}$ and $YBa_{2-x}Cu_{3}O_{6+x}$ are considered as a system of the electron and hole polar pseudo-Jahn-Teller $CuO_{4}$ centers $[{CuO}_{4}^{7-}]_{JT}$ and $[CuO_{4}^{5-}]_{JT}$, respectively, or…
The electronic, magnetic and orbital structures of KCrF_3 are determined in all its recently identified crystallographic phases (cubic, tetragonal, and monoclinic) with a set of {\it ab initio} LSDA and LSDA+U calculations. The…
A methodology is worked out to retrieve the numerical values of all the main parameters of the six-dimensional adiabatic potential energy surface (APES) of a polyatomic system with a quadratic T-term Jahn-Teller effect (JTE) from ultrasound…
The longitudinal ultrasonic sound velocity and attenuation, the resistivity, and lattice parameters were studied as a function of temperature from 30 K to 300 K in La1-xCaxMnO3 (0.5<x<0.9). For all the samples, a dramatic stiffening of the…
The insulator-bad metal transition observed in the Jahn-Teller (JT) magnets orthonickelates RNiO$_3$ (R = rare earth or yttrium Y) is considered to be a canonical example of the Mott transition, traditionally described in the framework of…
The electronic structure and magnetic properties of disordered Fe$_{x}$Pd$_{100-x}$ alloys $(50 < x < 85)$ are investigated in the framework of density functional theory using the full potential local orbital method (FPLO). Disorder is…