R.J. Cava

Charge-transfer excitations are of paramount importance for understanding the electronic structure of copper-oxide based high-temperature superconductors. In this study, we investigate the response of a BiSrCaCuO crystal to the charge redistribution induced by an infrared ultrashort pulse. Element-selective time-resolved core-level photoelectron spectroscopy with a high energy resolution allows disentangling the dynamics of oxygen ions with different coordination and bonds thanks to their different chemical shifts. Our experiment shows that the O 1s component arising from the Cu–O planes is significantly perturbed by the infrared light pulse. Conversely, the apical oxygen, also coordinated with Sr ions in the Sr-O planes, remains unaffected. This result highlights the peculiar behavior of the electronic structure of the Cu–O planes. It also unlocks the way to study the out-of-equilibrium electronic structure of …

Er3+ plus V5+, and Er3+ plus Nb5+ co-doped CaWO4, formulas Ca1-xErxW1-xMxO4, were synthesized in air by a conventional solid-state method. A color change from white to pink was observed in the final products. An equal fraction of dopants was employed to obtain charge neutrality, and the limits of the solubility for our conditions are lower than x=0.15. The magnetic susceptibility data shows that that the magnetic coupling becomes increasingly antiferromagnetic with increasing Er3+content. The Curie-Weiss fit and isothermal magnetization imply that different degrees of spin-orbit coupling appear to be present in the two doping systems. No transitions were observed in the heat capacity data above 0.4 K.

W49. 00001: Spin-Photon Entanglement of a Single Rare-Earth-Ion at the Telecom Band*

Co3V2O8 features spin-3/2 moments arrayed on a kagome staircase lattice. A spin density wave with a continuously evolving propagation vector of k = (0, δ, 0), showing both incommensurate states and multiple commensurate lock-ins, is observed at temperatures above the ferromagnetic ground state. Previous work has suggested that this changing propagation vector could be driven by changes in exchange interactions due to Co atom displacements. We present a straightforward model showing that a Hamiltonian with competing (but temperature independent) interactions can semi-quantitatively reproduce this behavior using a mean field approximation. The simulated spin density wave magnetic structures feature buckled kagome planes that are either ferromagnetically or antiferromagnetically ordered. Propagation vectors that differ from δ = 1/2 will have multiple different ways of arranging these ferromagnetic …

A16. 00004: Pressure evolution of crystal structure, magnetism, and electrical resistivity in bilayer and trilayer nickelates*

We synthesize four novel quasi-one-dimensional organic–inorganic hybrid iron chloride compounds (CH3NH3FeCl3, CH(NH2)2FeCl3, C(NH2)3FeCl3, and C3H5N2FeCl3) and characterize their structural and magnetic properties. These materials crystallize in a hexagonal perovskite-type structure, constituting a triangular array of face-sharing iron chloride octahedra chains running along the c-axis, isolated from one another by the organic cation. Through magnetization and heat capacity measurements, we find that the intrachain coupling is weakly ferromagnetic for each variant. Importantly, this work underscores the utility of solid-state chemistry approaches in synthesizing new organic–inorganic hybrid materials.

An unreported rhenium-based calcium aluminum sodalite (CARe sodalite) has been synthesized by a traditional solid-state method. The rhenium is located in the sodalite β-cage and can be reduced under 5% H2 forming gas without breaking the cage framework. Preliminary characterizations of the structural, optical, and magnetic properties are reported.Graphical abstract

We report superconductivity in the full Heusler compound LiPd2Si (space group Fm3̅m, No. 225) at a critical temperature of Tc = 1.3 K and a normalized heat capacity jump at Tc, ΔC/γTc = 1.1. The low-temperature isothermal magnetization curves imply type-I superconductivity, as previously observed in LiPd2Ge. We show, based on density functional theory calculations and using the molecular orbital theory approach, that while LiPd2Si and LiPd2Ge share the Pd cubic cage motif that is found in most of the reported Heusler superconductors, they show distinctive features in the electronic structure. This is due to the fact that Li occupies the site which, in other compounds, is filled with an early transition metal or a rare-earth metal. Thus, while a simple valence electron count–property relationship is useful in predicting and tuning Heusler materials, inclusion of the symmetry of interacting frontier orbitals is also …