Related papers: Stress Induced Charge-Ordering Process in LiMn2O4
Spinel Li$_x$Mn$_2$O$_4$ is a key cathode material that is used extensively in commercial Li-ion batteries. A challenge with this material has been that the capacity of the battery fades with cycling, an effect that can be traced to the…
The Jahn-Teller effect (JTE) is central to the understanding of the physical and chemical properties of a broad variety of molecules and materials. Whereas the manifestations of the JTE on stationary properties of matter are relatively well…
We develop a microscopic theory for the charge ordering (CO) transitions in the spinels AlV$_2$O$_4$ and LiV$_2$O$_4$ (under pressure). The high degeneracy of CO states is lifted by a coupling to the rhombohedral lattice deformations which…
We present x-ray, neutron scattering and heat capacity data that reveal a coupled first-order magnetic and structural phase transition of the metastable mixed-valence post-spinel compound Mn$_3$O$_4$ at 210 K. Powder neutron diffraction…
In complex electronic materials, coupling between electrons and the atomic lattice gives rise to remarkable phenomena, including colossal magnetoresistance and metal-insulator transitions. Charge-ordered phases are a prototypical…
The lacunar spinel GaNb$_4$Se$_8$ is a tetrahedral cluster Mott insulator where spin-orbit coupling on molecular orbitals and Jahn-Teller energy scales are competitive. GaNb$_4$Se$_8$ undergoes a structural and anti-polar ordering…
At room temperature, bulk La$_{7/8}$Sr$_{1/8}$MnO$_3$ is in the dynamic Jahn--Teller O$^*$ phase, but undergoes a transition to a static, magnetically ordered Jahn--Teller phase at lower temperatures. Here we study a $6$ unit cells thin…
In spinel-type nickelate NiRh$_2$O$_4$, magnetic ordering is observed upon the sample synthesized via kinetically controlled low-temperature solid-state metathesis, as opposed to previously-reported samples obtained through conventional…
The Fe intercalated transition metal dichalcogenide (TMD), Fe$_{1/3}$NbS$_2$, exhibits remarkable resistance switching properties and highly tunable spin ordering phases due to magnetic defects. We conduct synchrotron X-ray scattering…
From low-temperature Synchrotron X-ray diffraction, a precise thermal characterization of octahedral distortions in single phase Ruddlesden-Popper Ca3Mn2O7 is performed. Highly sensitive close-steps temperature dependences of Mn-O-Mn bond…
Cooperative Jahn-Teller ordering is well-known to drive the cubic $Fd\overline{3}m$ to tetragonal $I$4$_1$/$amd$ structural distortion in Mn$_3$O$_4$ at 1170 $^{\circ}$C. Further structural distortion occurs in Mn$_3$O$_4$ upon magnetic…
The results of 13C NMR spectra and nuclear spin-lattice relaxation rate 1/T_1 for the quasi-one-dimensional quarter-filled organic material (TMTTF)2SCN are presented. A new inhomogeneous line appears below the anion ordering temperature…
We use first-principles theory to predict that the application of uniaxial compressive strain leads to a transition from an antiferromagnetic insulator to a ferromagnetic half-metal phase in LaMnO$_3$. We identify the Q2 Jahn-Teller mode as…
Using first-principles calculations based on the density functional theory, we show a strong strain dependence of magnetic order in (LaMnO$_{3}$)$_n$/(SrMnO$_{3}$)$_{2n}$ (001) superlattices with $n=1,2$. The epitaxial strain lifts the…
Charge-ordering phenomena have been highly topical over the last few years. A phase transition towards a charge ordered state has been observed experimentally in several classes of materials. Among them, many studies have been devoted to…
We report the magnetic properties of $A$-site spinel compound MnSc$_2$Se$_4$. The macroscopic magnetic measurements uncovers successive magnetic transitions at $T_{\rm{N1}}$= 2.04 K, followed by two further transitions at $T_{\rm{N2}}$=1.8…
Distortions of the oxygen sublattice couple to $e_g$ orbitals of Mn$^{3+}$ and drive a cooperative Jahn-Teller (orbital ordering) transition in LaMnO$_3$. A simple model for this transition is studied. Without further adjustment, the model…
Aiming at increasing the ferroelectric polarization in AFM-E ortho-\hmo, we investigate the in-plane strain effects on both the magnetic configuration and the polarization by means of density functional theory calculations and model…
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…
Charge-order-driven ferroelectrics are an emerging class of functional materials, distinct from conventional ferroelectrics, where electron-dominated switching can occur at high frequency. Despite their promise, only a few systems…