相关论文: Pressure-induced metal-insulator and spin-state tr…
The trilayer nickelate Nd$_4$Ni$_3$O$_{10-\delta}$ ($\delta \approx$ 0.15) was investigated by the measurements of x-ray diffraction, electrical resistivity, magnetic susceptibility, and heat capacity. The crystal structure data suggest a…
A mixed classical-quantum density functional theory is used to calculate pair correlations and the free energy of a spin-polarized Hydrogen plasma. A transition to an atomic insulator phase is estimated to occur around r_s=2.5 at T=10^4K,…
We present a combination of first-principles and experimental results regarding the structural and magnetic properties of olivine-type LiFePO$_4$ under pressure. Our investigations indicate that the starting $Pbnm$ phase of LiFePO$_4$…
A two-dimensional gas of non-interacting quasiparticles in a nearly periodic potential is considered at zero temperature. The potential is a superposition of a periodic potential, induced by the charge density wave of a Wigner crystal, and…
The recent discovery of high-temperature superconductivity in high-pressurized La$_3$Ni$_2$O$_{7-\delta}$ has garnered significant attention. Using density functional theory, we investigate the magnetic properties of…
We present a study of the static magnetic properties and spin dynamics in Cobalt valence tautomers (VT), molecules where a low-spin (LS) to high-spin (HS) crossover driven by an intramolecular electron transfer can be controlled by the…
The magnetic, electric and thermal properties of the ($Ln_{1-y}$Y$_{y}$)$_{0.7}$Ca$_{0.3}$CoO$_3$ perovskites ($Ln$~=~Pr, Nd) were investigated down to very low temperatures. The main attention was given to a peculiar metal-insulator…
Ultra-high resolution synchrotron diffraction data for $\rm GdBaCo_2O_{5.5}$ throw new light on the metal-insulator transition of Co$^{3+}$ Ba-cobaltites. An anomalous expansion of CoO$_6$ octahedra is observed at the phase transition on…
A metal-insulator transition (MIT) in BiFeO$_3$ under pressure was investigated by a method combining Generalized Gradient Corrected Local Density Approximation with Dynamical Mean-Field Theory (GGA+DMFT). Our paramagnetic calculations are…
We investigate the spin injection and the spin transport in paramagnetic insulators described by simple Heisenberg interactions using auxiliary particle methods. Some of these methods allow access to both paramagnetic states above magnetic…
High pressure can provoke spin transitions in transition metal-bearing compounds. These transitions are of high interest not only for fundamental physics and chemistry, but also may have important implications for geochemistry and…
Transport and magnetic measurements and structural and NMR studies have been carried out on (Pr1-yR'y)1-xAxCoO3 {R'=(rare earth elements and Y); A=(Ca, Ba and Sr)} at ambient pressure or under high pressure. The system exhibits a phase…
The recent discovery of high-temperature superconductivity in pressurized Ruddlesden-Popper nickelates stimulated intense research into their correlated electron physics. Establishing the diversity of ground states across different…
La$_3$Ni$_2$O$_7$, a bilayer nickelate with Ruddlesden-Popper structure, undergoes a pressure-induced structural transition from a tilted Amam phase to an untilted Fmmm (or I4/mmm) phase near 10-15 GPa, concomitant with the emergence of…
We perform a comprehensive theoretical study of the pressure-induced evolution of the electronic structure, magnetic state, and phase stability of the late transition metal monoxides MnO, FeO, CoO, and NiO using a fully charge…
Single crystals of the metallic Ruddlesden-Popper trilayer nickelates R$_4$Ni$_3$O$_{10}$ (R=La, Pr) were successfully grown using an optical-image floating zone furnace under oxygen pressure (pO$_2$) of 20 bar for La$_4$Ni$_3$O$_{10}$ and…
We present measurements of the magnetic susceptibility and of the thermal expansion of a LaCoO$_3$ single crystal. Both quantities show a strongly anomalous temperature dependence. Our data are consistently described in terms of a…
A muon-spin rotation/relaxation ($\mu$SR) study of the trilayer Ruddlesden--Popper nickelate Pr$_4$Ni$_3$O$_{10}$ was performed at ambient pressure and under hydrostatic pressure up to 2.2 GPa. Three magnetic transitions were identified at…
The electronic property and magnetic susceptibility of Ce$_3$Pd$_3$Bi$_4$ were systemically investigated from 18 K to 290 K for varying values of cell-volume using dynamic mean-field theory coupled with density functional theory. By…
The X-ray absorption near-edge structure (XANES) of Mn in a spin-crossover compound, [Mn$^{\textrm{III}}$(taa)], was studied in pulsed high magnetic fields up to 37T. By applying magnetic fields to the low-temperature low-spin (LS) state,…