Correction to "Competing Magnetism in Layered Mixed Transition Metal Chalcogenides KCo Ni Se, KCo Ni S, and CsCo Ni Se".

[This corrects the article DOI: 10.1021/acs.chemmater.

Competing Magnetism in Layered Mixed Transition Metal Chalcogenides KCo Ni Se, KCo Ni S, and CsCo Ni Se.

Layered transition metal chalcogenides are a versatile class of compounds that exhibit exotic physical phenomena, including superconductivity, thermoelectric properties and magnetic properties. The magnetic properties of ThCrSi-type solid solutions KCo Ni ( = S, Se; 0 ≤ ≤ 2) with metallic properties were probed using magnetometry and powder neutron diffraction (PND). KCoSe is ferromagnetic below ∼90 K and powder neutron diffraction (PND) showed evidence for long-range ferromagnetic order with localized moments of 0.

Disorder-induced universality and scaling in hole-doped iron-based superconductors.

Iron-based superconductors exhibit various magnetic and electronic phases that are highly sensitive to structural and chemical modifications. Elucidating the origins of these phases remains a central challenge. Here, using neutron and x-ray diffraction, we uncover a universal phase diagram that identifies disorder as a hidden tuning parameter governing these phase transitions.

CoFeO-CoFeO core-shell nanoparticles with colossal exchange bias.

The exchange bias (EB) effect is widely utilized in spintronics with 2D materials like thin films. Exploring the EB effect in nanoparticles opens up tremendous opportunities, such as miniaturization of devices, enhanced efficiency, and tunable properties, all of which are size-dependent. Due to the increased surface area to volume ratio, magnetic nanoparticles display unique characteristics, allowing for the manipulation of their magnetic properties, such as the EB effect commonly observed between antiferromagnetic (AFM) and ferro-/ferrimagnetic (FM/FiM) materials.

Cation Exchange as a Route to Introduce Magnetism to Hybrid-Improper Polar Phases.

The pseudo Ruddlesden-Popper phase LiCaTaO is converted to ZnCaTaO, FeCaTaO, or CoCaTaO by reaction with the corresponding transition-metal dichloride. Diffraction data reveal that ZnCaTaO adopts a polar crystal structure (2) with the Zncations ordered into stripes within the interlayer coordination sites, and the TaO units adopt an /-() tilting pattern. In contrast, FeCaTaO and CoCaTaO adopt polar structures (2) with the transition-metal cations ordered in a checkerboard pattern within the interlayer coordination sites, and the TaO units adopt an / tilting pattern.

Fluctuation-driven topological Hall effect in room-temperature itinerant helimagnet FeGa.

The topological Hall effect (THE) is a hallmark of a non-trivial geometric spin arrangement in a magnetic metal, originating from a finite scalar spin chirality (SSC). The associated Berry phase is often a consequence of non-coplanar magnetic structures identified by multiple k-vectors. For single - k magnetic structures however with zero SSC, the emergence of a finite topological Hall signal presents a conceptual challenge.

Magnetic structure determination of multiple phases in the multiferroic candidate GdCrO.

Due to their potential applications in low-power consumption and/or multistate memory devices, multiferroic materials have attracted a lot of attention in the condensed matter community. As part of the effort to identify new multiferroic compounds, perovskite-based GdCrO was studied in both bulk and thin film samples. A strong enhancement of the capacitance in a field suggested ferroelectric behaviour but significant leakage and no well developed P-E hysteresis loops were observed.

Structural Elucidation of NaNiO, a Dynamically Stabilized Cathode Phase with Nickel Charge and Sodium Vacancy Ordering.

NaNiO (NNO) has been investigated as a promising sodium-ion battery cathode material, but it is limited by degradation-induced capacity fade. On desodiation, NNO forms multiple phases with large superstructures due in part to Na-ion vacancy ordering; however, their structures are unknown. Here, we report a structural solution to the NaNiO (P3) desodiated phase using combined Rietveld refinement of high-resolution synchrotron X-ray (SXRD) and neutron powder diffraction (NPD) data, magnetic susceptibility, and Na solid-state nuclear magnetic resonance (ssNMR) spectroscopy.

MFM-300 as High-Performance Sorbents for Water-Adsorption-Driven Cooling.

Adsorption-driven heat transfer is potentially a sustainable technology to decarbonize heating and cooling. However, the development of high-performance adsorbent-adsorbate working pairs remains extremely challenging. Here, we report a metal-organic framework/water working pair that can operate at an ultralow driving temperature (62 °C), showing a high coefficient of performance (COP) of 0.

Bilayer Kagome Ferrimagnet Exhibiting Exceptional Spontaneous Exchange Bias in TbMn(Ge,Ga).

Manipulating interlayer interactions in two-dimensional (2D) materials has led to intriguing behaviors. Borrowing these 2D signatures to bulk materials is likely to unlock exceptional properties. Here, we report an emergent 2D-like bilayer Kagome ferrimagnet through reducing the interbilayer magnetic interaction to nearly zero.

Magnetic structure of MnGaC thin film by neutron scattering.

MAX phases are a family of atomically laminated materials with various potential applications. MnGaC is a prototype magnetic MAX phase, where complex magnetic behaviour arises due to competing interactions. We have resolved the room temperature magnetic structure of MnGaC by neutron diffraction from single-crystal thin films and we propose a magnetic model for the low temperature phase.

Compass-model physics on the hyperhoneycomb lattice in the extreme spin-orbit regime.

The physics of spin-orbit entangled magnetic moments of 4d and 5d transition metal ions on a honeycomb lattice has been much explored in the search for unconventional magnetic orders or quantum spin liquids expected for compass spin models, where different bonds in the lattice favour different orientations for the magnetic moments. Realising such physics with rare-earth ions is a promising route to achieve exotic ground states in the extreme spin-orbit limit; however, this regime has remained experimentally largely unexplored due to major challenges in materials synthesis. Here we report the successful synthesis of powders and single crystals of β-NaPrO, with 4f Pr j = 1/2 magnetic moments arranged on a hyperhoneycomb lattice with the same threefold coordination as the planar honeycomb.

Boosting Adsorption and Selectivity of Acetylene by Nitro Functionalisation in Copper(II)-Based Metal-Organic Frameworks.

Purification and storage of acetylene (CH) are important to many industrial processes. The exploitation of metal-organic framework (MOF) materials to address the balance between selectivity for CH vs carbon dioxide (CO) against maximising uptake of CH has attracted much interest. Herein, we report that the synergy between unsaturated Cu(II) sites and functional groups, fluoro (-F), methyl (-CH), nitro (-NO) in a series of isostructural MOF materials MFM-190(R) that show exceptional adsorption and selectivity of CH.

Designing giant Hall response in layered topological semimetals.

Noncoplanar magnets are excellent candidates for spintronics. However, such materials are difficult to find, and even more so to intentionally design. Here, we report a chemical design strategy that allows us to find a series of noncoplanar magnets-LnSn (Ln = Dy, Tb)-by targeting layered materials that have decoupled magnetic sublattices with dissimilar single-ion anisotropies and combining those with a square-net topological semimetal sublattice.

Nonaqueous Synthesis of Low-Vacancy Chromium Hexacyanochromate.

Prussian blue analogues (PBAs) are a highly tunable family of materials with properties suitable for a wide variety of applications. Although their straightforward aqueous synthesis allows for the facile preparation of a diverse set of compositions, the use of water as the solvent has hindered the preparation of specific compositions with highly sought-after properties. A typical example is Cr[Cr(CN)]: its predicted strong magnetic interactions have motivated many attempts at its synthesis but with limited success.

Kitaev interactions through extended superexchange pathways in the Ru honeycomb magnet RuPSiO.

Magnetic materials are composed of the simple building blocks of magnetic moments on a crystal lattice that interact via magnetic exchange. Yet from this simplicity emerges a remarkable diversity of magnetic states. Some reveal the deep quantum mechanical origins of magnetism, for example, quantum spin liquid (QSL) states in which magnetic moments remain disordered at low temperatures despite being strongly correlated through quantum entanglement.

A Flexible Phosphonate Metal-Organic Framework for Enhanced Cooperative Ammonia Capture.

Ammonia (NH) production in 2023 reached 150 million tons and is associated with potential concomitant production of up to 500 million tons of CO each year. Efforts to produce green NH are compromised since it is difficult to separate using conventional condensation chillers, but in situ separation with minimal cooling is challenging. While metal-organic framework materials offer some potential, they are often unstable and decompose in the presence of caustic and corrosive NH.

Trace benzene capture by decoration of structural defects in metal-organic framework materials.

Capture of trace benzene is an important and challenging task. Metal-organic framework materials are promising sorbents for a variety of gases, but their limited capacity towards benzene at low concentration remains unresolved. Here we report the adsorption of trace benzene by decorating a structural defect in MIL-125-defect with single-atom metal centres to afford MIL-125-X (X = Mn, Fe, Co, Ni, Cu, Zn; MIL-125, TiO(OH)(BDC) where HBDC is 1,4-benzenedicarboxylic acid).

Low-Temperature Ferromagnetic Order in a Two-Level Layered Co Material.

The magnetic properties of a 2D layered material consisting of high-spin Co complexes, [Co(NHNH)(HO)Cl]Cl ( ), have been extensively characterized using electron paramagnetic resonance, magnetic susceptibility, and low-temperature heat capacity measurements. Electron paramagnetic resonance spectroscopy studies suggest that below 50 K, the = 3/2 orbital triplet state of Co is gradually depopulated in favor of the = 1/2 spin state, which is dominant below 20 K. In light of this, the magnetic susceptibility has been fitted with a two-level model, indicating that the interactions in this material are much weaker than previously thought.

Giant Room-Temperature Topological Hall Effect in a Square-Net Ferromagnet LaMnGe.

A topological magnetic material showcases a multitude of intriguing properties resulting from the compelling interplay between topology and magnetism. These include notable phenomena such as a large anomalous Nernst effect (ANE), an anomalous Hall effect (AHE), and a topological Hall effect (THE). In most cases, topological transport phenomena are prevalent at temperatures considerably lower than room temperature, presenting a challenge for practical applications.

Competition between Anion-Deficient Oxide and Oxyhydride Phases during the Topochemical Reduction of LaSrCoRuO.

Binary metal hydrides can act as low-temperature reducing agents for complex oxides in the solid state, facilitating the synthesis of anion-deficient oxide or oxyhydride phases. The reaction of LaSrCoRuO, with CaH in a sealed tube yields the face-centered cubic phase LaSrCoRuOH. The reaction with LiH under similar conditions converts LaSrCoRuO to a mixture of tetragonal LaSrCoRuOH and cubic LaSrCoRuOH.

High adsorption of ammonia in a titanium-based metal-organic framework.

We report the high adsorption of NH in a titanium-based metal-organic framework, MFM-300(Ti), comprising extended [TiO] chains linked by biphenyl-3,3',5,5'-tetracarboxylate ligands. At 273 K and 1 bar, MFM-300(Ti) shows an exceptional NH uptake of 23.4 mmol g with a record-high packing density of 0.

Revisiting the hydrogenation behavior of NdGa and its hydride phases.

NdGa hydride and deuteride phases were prepared from high-quality NdGa samples and their structures characterized by powder and single-crystal X-ray diffraction and neutron powder diffraction. NdGa with the orthorhombic CrB-type structure absorbs hydrogen at hydrogen pressures ≤ 1 bar until reaching the composition NdGaH(D), which maintains a CrB-type structure. At elevated hydrogen pressure additional hydrogen is absorbed and the maximum composition recovered under standard temperature and pressure conditions is NdGaH(D) with the LaGaH-type structure.

Exceptional capture of methane at low pressure by an iron-based metal-organic framework.

The selective capture of methane (CH) at low concentrations and its separation from N are extremely challenging owing to the weak host-guest interactions between CH molecules and any sorbent material. Here, we report the exceptional adsorption of CH at low pressure and the efficient separation of CH/N by MFM-300(Fe). MFM-300(Fe) shows a very high uptake for CH of 0.