Related papers: La-site shift as probe for Jahn-Teller effect
The local structure about the Mn site in the half doped system La0.5Ca0.5MnO3 was measured in magnetic fields up 10 T to probe the melting of the charge ordered state. Examination of the Mn-O and Mn-Mn correlations reveal three distinct…
Chromium (II) fluoroperovskites $A\mathrm{CrF_3}(A\mathrm{=Na^+,K^+})$ are strongly correlated Jahn-Teller active materials at low temperatures. In this paper, we examine the role that the $A$-site ion plays in this family of…
The phase diagrams of LaMnO$_3$ perovskites have been intensely studied due to the colossal magnetoresistance (CMR) exhibited by compositions around the $\frac{3}{8}^{th}$ doping level. However, phase segregation between ferromagnetic (FM)…
In this work, we report an atomic scale study on the ferromagnetic insulator manganite LaMnO$_{3.12}$ using $\gamma-\gamma$ PAC spectroscopy. Data analysis reveals a nanoscopic transition from an undistorted to a Jahn-Teller-distorted local…
The latent heat (L) associated with the orbital order-disorder transition at T_JT is found to depend significantly on the average particle size (d) of LaMnO3. It rises slowly with the decrease in d down to ~100 nm and then jumps by more…
We have analyzed the experimental evidence of charge and orbital ordering in La0.5Sr1.5MnO4 using first principles band structure calculations. Our results suggest the presence of two types of Mn sites in the system. One of the Mn sites…
We study a two dimensional, two-band double-exchange model for $e_g$ electrons coupled to Jahn-Teller distortions in the presence of quenched disorder using a recently developed Monte-Carlo technique. In the absence of disorder the…
We have investigated the influence of B - site doping on the crystal and magnetic structure in $La_{0.5}Ca_{0.5}Mn_{1-x}B_{x}O_{3}$ (B= Fe, Ru, Al and Ga) compounds using neutron diffraction, SANS, magnetization and resistivity techniques.…
Using the degenerate double exchange Hamiltonian with on-site Coulomb interactions we show that there is an instability towards the displacement of the manganese ion in La_{1-x}Ca_{x}MnO_{3}. The result is a dipole moment due to the charge…
We have investigated the nature of ferromagnetic order and phase transitions in two dimensional (2D) van der Waals (vdW) layered material, Fe$_4$GeTe$_2$ through measurements of magnetization, magneto-caloric Effect (MCE), and heat…
The dynamical Jahn--Teller effect on fullerene sites in insulating Cs$_3$C$_{60}$ is investigated fully ab initio. The vibronic excitations of rotational type are at $\ge$65 cm$^{-1}$ while the net kinetic contribution to the Jahn--Teller…
We present the results of broadband dielectric spectroscopy of GaMo$_4$S$_8$, a lacunar spinel system that recently was shown to exhibit non-canonical, orbitally-driven ferroelectricity. Our study reveals complex relaxation dynamics of this…
The doping induced insulator-metal transition in $La_{1-x}Sr_{x}TiO_{3}$ is studied using the ab-initio LDA+DMFT method. Combining the LDA bandstructure for the actual, distorted structure found recently with multi-orbital DMFT to treat…
We propose a three-dimensional multi-orbital tight-binding model for rare-earth nickelates RNiO$_3$ that treats charge, spin, orbital, and lattice degrees of freedom on equal footing. All model parameters, including the on-site interactions…
K$_2$ReCl$_6$ belongs to the antifluorite family and exhibits a sequence of structural transitions above the onset of magnetic order at $T_N$ = 12 K. Because of its 5d3 electronic configuration in an octahedral coordination, the ground…
In this work we investigate the magnetic field dependence of Ag octahedra rotation (tilt) and B2g symmetric stretching modes frequency at different temperatures. Our field-dependent Raman investigation at 10K is interpreted by an ionic…
The Jahn-Teller distortive transition of \lmo is described by a modified 3-state Potts model. The interactions between the three possible orbits depends both on the orbits and their relative orientation on the lattice. Values of the two…
The first-order metal-insulator transition (MIT) in paramagnetic $V_{2}O_{3}$ is studied within the ab-initio scheme LDA+DMFT, which merges the local density approximation (LDA) with dynamical mean field theory (DMFT). With a fixed value of…
We report on Raman scattering measurements of the A-site ordered YBaMn2O6 in the wide temperature range of 10-650K. Upon cooling almost all phonon modes show pronounced temperature dependencies of frequency, linewidth, and scattering…
A classical model for the lattice distortions of $\lax$ is derived and, in a mean field approximation, solved. The model is based on previous work by Kanamori and involves localized Mn d-electrons (which induce tetragonal distortions of the…