相关论文: Direct observation of charge order in triangular m…
We report a high-resolution neutron diffraction study on the orbitally-degenerate spin-1/2 hexagonal antiferromagnet AgNiO2. A structural transition to a tripled unit cell with expanded and contracted NiO6 octahedra indicates root(3) x…
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…
A novel metallic and magnetic transition metal oxide Ag2NiO2 is studied by means of resistivity, magnetic susceptibility, specific heat and X-ray diffraction. The crystal structure is characterized by alternating stacking of a Ni3+O2 layer…
X-ray resonant scattering at the K-edge of transition metal oxides is shown to measure the orbital order parameter, supposed to accompany magnetic ordering in some cases. Virtual transitions to the 3d-orbitals are quadrupolar in general. In…
Antiferromagnetic (AF) order of U$_{2}$Pt$_{6}$Ga$_{15}$ with the ordering temperature $T_{\rm N}$ = 26 K was investigated by resonant X-ray scattering and neutron diffraction on single crystals. This compound possesses a unique crystal…
We present a combined study of Ni $K$-edge resonant x-ray scattering and density functional calculations to probe and distinguish electronically driven ordering and lattice distortions in nickelate heterostructures. We demonstrate that due…
We have used element specific X-ray resonant scattering to investigate the M edge resonances in a single crystal of \unpo. Earlier neutron diffraction and M\"{o}ssbauer studies had shown the presence of long-range AF order below T$_{N}$ =…
The temperature evolution of the crystal and magnetic structures of ferroelectric sulfide AgCrS2 have been investigated by means of neutron scattering. AgCrS2 undergoes at TN = 41.6 K a first-order phase transition, from a paramagnetic…
We report the magnetic structure and electronic properties of the honeycomb antiferromagnet $\rm NaNi_2BiO_{5.66}$. We find magnetic order with moments along the $c$ axis for temperatures below $T_{c1}=6.3(1)\>{\rm K}$ and then in the…
We report on optical measurements of the 1D Heisenberg antiferromagnet KCuF3. The crystal-field excitations of the Cu2+ ions have been observed and their temperature dependence can be understood in terms of magnetic and exchange-induced…
We present a detailed analysis of light scattering experiments performed on the quarter-filled spin ladder compound $\alpha^\prime$-NaV$_{2}$O$_{5}$ for the temperature range 5 K$\le$T$\le$300 K. This system undergoes a phase transition…
Solution-grown single crystals of Fe2OBO3 were characterized by specific heat, Mossbauer spectroscopy, and x-ray diffraction. A peak in the specific heat at 340 K indicates the onset of charge order. Evidence for a doubling of the unit cell…
We report a comprehensive Cu L$_3$-edge resonant x-ray scattering study of two- and three-dimensional (2D and 3D) incommensurate charge correlations in single crystals of the underdoped high-temperature superconductor…
Zero-field muon-spin relaxation measurements of the frustrated triangular quantum magnet AgNiO2 are consistent with a model of charge disproportionation that has been advanced to explain the structural and magnetic properties of this…
The thermodynamics of the antiferromagnetic ordering transition in NiO and the photoelectron spectra in the antiferromagnetic phase are studied by the Variational Cluster Approximation. Using realistic Racah parameters to describe the…
The layered delafossite compound AgNiO$_2$ with $2H$ stacking symmetry undergoes a structural metal-to-metal transition at $T_{\rm S}\sim 365$ K. It has been described in the past as a charge-ordering transition, where local $S=1$ spins are…
We present a resonant x-ray scattering study of the octahedral tilt order between 50K and 310K in La_7/8Sr_1/8MnO_3. At the La L_II-edge the resonant (300) reflection probes cooperative tilts of the MnO_6-octahedra in this material, as…
We use resonant X-ray scattering at the nickel L$_{2,3}$ edges to investigate the interplay between orbital degrees of freedom and charge density waves (CDW) in the superconductor BaNi$_2$(As$_{1-x}$P$_x$)$_2$. Both the incommensurate and…
The silver ruthenium oxide AgRuO$_3$ consists of honeycomb [Ru$_2^{5+}$O$_6^{2-}$] layers, and can be considered an analogue of SrRu$_2$O$_6$ with a different intercalation stage. We present measurements of magnetic susceptibility and…
We have investigated the magnetic properties of Bi0.5Ca0.5MnO3 under ultrahigh magnetic fields by magnetization measurements. This compound shows the metamagnetic transition which indicates the magnetic field induced charge order melting at…