Fe- and B-Chains in the TiFeOsB Structure Type Derived from Chemical Twinning of the NbOsB Type: Experimental and Computational Investigations.

The complex metal-rich boride TiFeOsB (0 < , < 1), crystallizing in a new structure type (space group , no. 63), was prepared by arc-melting. The new structure contains both isolated boron atoms and zigzag boron chains (B-B distance of 1.

Triangular Arrangement of Ferromagnetic Iron Chains in the High-T Ferromagnet TiFe Os B.

Transition-metal borides (TMBs) containing B -fragment (n>3) have recently gained interest for their ability to enable exciting magnetic materials. Herein, we show that the B -containing TiFe Os B is a new ferromagnetic TMB with a Curie temperature of 523(2) K and a Weiss constant of 554(3) K, originating from the chain of M -triangles (M=64 %Fe+36 %Os). The new phase was synthesized from the elements by arc-melting, and its structure was elucidated by single-crystal X-ray diffraction.

It Runs in the BaAl Family: Relating the Structure and Properties of Middle Child LnCoGe (Ln = Pr, Nd, and Sm) to its Siblings LnCoGe and LnCoGe.

The BaAl prototype structure and its derivatives have been identified to host several topological quantum materials and noncentrosymmetric superconductors. Single crystals up to ∼3 mm × 3 mm × 5 mm of LnCoGe (Ln = Pr, Nd, and Sm) are obtained via flux growth utilizing Sn as metallic flux. The crystal structure is isostructural to the LuCoSi structure type in the crystallographic space group 2/.

Evidence of a coupled electron-phonon liquid in NbGe.

Whereas electron-phonon scattering relaxes the electron's momentum in metals, a perpetual exchange of momentum between phonons and electrons may conserve total momentum and lead to a coupled electron-phonon liquid. Such a phase of matter could be a platform for observing electron hydrodynamics. Here we present evidence of an electron-phonon liquid in the transition metal ditetrelide, NbGe, from three different experiments.

Antiferromagnetic Order and Spin-Canting Transition in the Corrugated Square Net Compound Cu(TeO)(SO)·HO.

Strongly correlated electrons in layered perovskite structures have been the birthplace of high-temperature superconductivity, spin liquids, and quantum criticality. Specifically, the cuprate materials with layered structures made of corner-sharing square-planar CuO units have been intensely studied due to their Mott insulating ground state, which leads to high-temperature superconductivity upon doping. Identifying new compounds with similar lattice and electronic structures has become a challenge in solid-state chemistry.

An Old Dog with New Tricks - Additions to the Cesium Lithium Chloride System: CsLiCl and the Hydrated CsLiCl · 4HO.

The CsCl/LiCl system has been studied for over a century now. Numerous phases have been predicted - only three have hitherto been found. We present the synthesis and single-crystal structure of the cesium lithium pentachloride CsLiCl, predicted earlier but with a different structure.

Graphene- and Phosphorene-like Boron Layers with Contrasting Activities in Highly Active MoB for Hydrogen Evolution.

Two different boron layers, flat (graphene-like) and puckered (phosphorene-like), found in the crystal structure of MoB show drastically different activities for hydrogen evolution, according to Gibbs free energy calculations of H-adsorption on MoB. The graphene-like B layer is highly active, whereas the phosphorene-like B layer performs very poorly for hydrogen evolution. A new Sn-flux synthesis permits the rapid single-phase synthesis of MoB, and electrochemical analyses show that it is one of the best hydrogen evolution reaction active bulk materials with good long-term cycle stability under acidic conditions.

Boron: Enabling Exciting Metal-Rich Structures and Magnetic Properties.

Boron's unique chemical properties and its reactions with metals have yielded the large class of metal borides with compositions ranging from the most boron-rich YB (used as monochromator for synchrotron radiation) up to the most metal-rich NdFeB (the best permanent magnet to date). The excellent magnetic properties of the latter compound originate from its unique crystal structure to which the presence of boron is essential. In general, knowing the crystal structure of any given extended solid is the prerequisite to understanding its physical properties and eventually predicting new synthetic targets with desirable properties.

Titanium Sulfides as Intercalation-Type Cathode Materials for Rechargeable Aluminum Batteries.

We report the electrochemical intercalation-extraction of aluminum (Al) in the layered TiS and spinel-based cubic CuTiS as the potential cathode materials for rechargeable Al-ion batteries. The electrochemical characterizations demonstrate the feasibility of reversible Al intercalation in both titanium sulfides with layered TiS showing better properties. The crystallographic study sheds light on the possible Al intercalation sites in the titanium sulfides, while the results from galvanostatic intermittent titration indicate that the low Al diffusion coefficients in the sulfide crystal structures are the primary obstacle to facile Al intercalation-extraction.

Boron-Dependency of Molybdenum Boride Electrocatalysts for the Hydrogen Evolution Reaction.

Molybdenum-based materials have been considered as alternative catalysts to noble metals, such as platinum, for the hydrogen evolution reaction (HER). We have synthesized four binary bulk molybdenum borides Mo B, α-MoB, β-MoB, and MoB by arc-melting. All four phases were tested for their electrocatalytic activity (linear sweep voltammetry) and stability (cyclic voltammetry) with respect to the HER in acidic conditions.

Direct Chemical Fine-Tuning of Electronic Properties in Sc Ir Pd B.

Crystal orbital Hamilton population (COHP) bonding analysis has predicted that ScPd B is the least stable compound of the entire series Sc Ir Pd B. Here, we report a systematic study of Sc Ir Pd B (x=3, 5 and 6) by means of B nuclear magnetic resonance (NMR), Knight shift (K) and nuclear spin-lattice relaxation rate (1/T ). NMR results combined with theoretical band structure calculations provide a measure of s- and non-s-character Fermi-level density of states.

Electronic pseudogap-driven formation of new double-perovskite-like borides within the Sc2Ir6-xTxB (T = Pd, Ni; x = 0-6) series.

Analysis of the electronic density of states of the hypothetical ternary double-perovskite-like phases "Sc2T6B (T = Ir, Pd, Ni)" reveals the presence of deep and large pseudogaps between 61 and 68 valence electrons (VE) as well as a strong peak at 69 VEs. Subsequently, crystal orbital Hamilton population (COHP) bonding analysis shows that the heteroatomic T-B and Sc-T interactions are optimized in Sc2Ir6B (63 VE) but not in "Sc2Pd6B (69 VE)" and "Sc2Ni6B (69 VE)", thus indicating less stability for these VE-richer phases. These findings point out the possibility of discovering new double-perovskite-like borides through chemical substitution and lead to the study of the Sc2Ir6-xPdxB and Sc2Ir6-xNixB (x = 0-6; VE = 63-69) series, for which powder samples and single crystals were synthesized by arc melting the elements.