Atomic-scale observation of geometric reconstruction in a fluorine-intercalated infinite layer nickelate superlattice.

Anion doping offers immense potential for tailoring material properties, but precise control over anion incorporation remains challenging due to complex synthesis and limitations in dopant detection. This study investigates F-ion intercalation within an infinite-layer NdNiO/SrTiO superlattice using a two-step process. We employ advanced four-dimensional scanning transmission electron microscopy (4D-STEM) coupled with electron energy loss spectroscopy (EELS) to map the F distribution and its impact on the atomic and electronic structure.

Water uptake of solids and its impact on ion transport.

The interaction modes of water with (polar) solids are manifold, comprising surface adsorption and incorporation into the bulk, both in molecular and in dissociated form. This Review discusses these processes and the respective pronounced effects on the ionic transport properties. The concentration as well as the mobility of ionic carriers can vary by orders of magnitude depending on the water content on or within a solid.

Visualizing the internal structure of the charge-density-wave state in CeSbTe.

The collective reorganization of electrons into a charge density wave has long served as a textbook example of an ordered phase in condensed matter physics. Two-dimensional square lattices with p electrons are well-suited to the realization of charge density waves, due to the anisotropy of the p orbitals and the resulting one dimensionality of the electronic structure. In spite of a long history of study of charge density waves in square-lattice systems, few reports have recognized the significance of a hidden orbital degree of freedom.

Nanofabrication for Nanophotonics.

Nanofabrication, a pivotal technology at the intersection of nanoscale engineering and high-resolution patterning, has substantially advanced over recent decades. This technology enables the creation of nanopatterns on substrates crucial for developing nanophotonic devices and other applications in diverse fields including electronics and biosciences. Here, this mega-review comprehensively explores various facets of nanofabrication focusing on its application in nanophotonics.

Gapped nodal planes and large topological Nernst effect in the chiral lattice antiferromagnet CoNbS.

The electronic structure of compensated antiferromagnets (CAF) creates large functional responses, reminiscent of ferromagnets and suitable for data storage and readout, despite (nearly) net-zero spontaneous magnetization. Many experimental signatures of CAF - such as giant thermoelectric Nernst effects - should be enhanced when two or more electronic bands are nearly degenerate in vicinity of the Fermi energy. Here, we report a zero-field, thermoelectric Nernst effect  >1 μV/K in the CAF CoNbS despite its tiny net magnetization  ~2 milli - μ.

Two-Dimensional, Chiral Colloidal Superlattices Engineered with DNA Origami.

Colloidal crystal engineering is widely recognized as a superior method for creating novel materials in multiple fields. However, achieving chiral superlattices of nanoparticles remains a considerable challenge so far. Here, we spread a two-dimensional (2D), microscale DNA origami array on substrate surfaces to maintain its planar conformation onto which DNA-encoded metal nanoparticles are attached to designated positions, thereby creating 2D chiral superlattices.

Dioxocobaltate(II)-anion in calcium vanadate apatite: partial ordering, magnetic anisotropy, and slow relaxation of magnetization.

Polycrystalline ceramic and small single-crystal samples of Co-containing calcium vanadate(V) with apatite structure were prepared for the first time. The Co ions enter the apatite trigonal channels formally substituting protons of the OH groups and form separate O-Co-O atomic groups elongated in the direction, Co being additionally weakly coordinated to an oxygen atom of a VO group. At a high Co content, the hexagonal apatite structure undergoes a triclinic distortion followed by partial ordering of the Co ions.

DNA‑Directed Assembly of Photonic Nanomaterials for Diagnostic and Therapeutic Applications.

DNA-directed assembly has emerged as a versatile and powerful approach for constructing complex structured materials. By leveraging the programmability of DNA nanotechnology, highly organized photonic systems can be developed to optimize light-matter interactions for improved diagnostics and therapeutic outcomes. These systems enable precise spatial arrangement of photonic components, minimizing material usage, and simplifying fabrication processes.

Spiral spin liquid noise.

An emerging concept for identification of different types of spin liquids [C. Broholm , , eaay0668 (2020)] is through the use of spontaneous spin noise [S. Chatterjee, J.

On the applicability of CCSD(T) for dispersion interactions in large conjugated systems.

In light of the recent discrepancies reported between fixed node diffusion Monte Carlo and local natural orbital coupled cluster with single, double, and perturbative triples [CCSD(T)] methodologies for non-covalent interactions in large molecular systems [Al-Hamdani et al., Nat. Commun.

Reliability of the Transmission Line Method and Reproducibility of the Measured Contact Resistance of Organic Thin-Film Transistors.

Using the transmission line method (TLM), we extracted the contact resistance of organic thin-film transistors (TFTs) based on five different vacuum-deposited small-molecule semiconductors fabricated on over 500 substrates. In the first part of this report, we illustrate how the reliability of the TLM analysis is affected by the statistical uncertainty that arises from the fitting procedure and by the systematic error that is introduced if the actual channel length of the TFTs deviates from the nominal channel length. In the second part, we show that the contact resistance of organic TFTs varies significantly from one fabrication run to the next (and even across substrates fabricated within the same fabrication run), no matter how much care is taken to keep all controllable fabrication-process parameters constant.

Ultrafast phonon-mediated dephasing of color centers in hexagonal boron nitride probed by electron beams.

Defect centers in hexagonal boron nitride (hBN) have been extensively studied as room-temperature single-photon sources. The electronic structure of these defects exhibits strong coupling to phonons, as evidenced by the observation of phonon sidebands in both photoluminescence and cathodoluminescence spectra. However, the dynamics of the electron-phonon coupling as well as phonon-mediated dephasing of the color centers in hBN remain unexplored.

Upconversion Nanoparticle-Covalent Organic Framework Core-shell Particles as Therapeutic Microrobots Trackable With Optoacoustic Imaging.

Despite the development of various medical imaging contrast agents, integrating contrast signal generation with therapeutic and microrobotic functions remains challenging without complicated fabrication processes. In this study, upconversion nanoparticle-covalent organic framework (UCNP-COF) core-shell sub-micron particles are developed that function as therapeutic microrobots trackable with multi-spectral optoacoustic tomography (MSOT) imaging and can be loaded with desired therapeutic molecular agents in a customizable manner. The mechanism of optoacoustic signal generation in UCNP-COF particles is attributed to the quenching of upconversion luminescence emitted by the UCNPs, which is absorbed by the encapsulating COF and subsequently converted into acoustic waves.

Interplay between multipolar order and multipole-induced superconductivity in PrTiAl.

Multipolar moments entail a new route to tackle frontier problems in superconductivity (SC). A key progress in the search for multipolar SC is the discovery of PrTrAl (Tr = Ti, V), which possesses quadrupolar and octupolar but no magnetic dipolar moments. The Kondo entanglement of these multipolar moments with conduction electrons leads to exotic SC within the multipolar ordered phase, though the precise nature of the SC remains unexplored.

Band-Gap Regression with Architecture-Optimized Message-Passing Neural Networks.

Graph-based neural networks and, specifically, message-passing neural networks (MPNNs) have shown great potential in predicting physical properties of solids. In this work, we train an MPNN to first classify materials through density functional theory data from the AFLOW database as being metallic or semiconducting/insulating. We then perform a neural-architecture search to explore the model architecture and hyperparameter space of MPNNs to predict the band gaps of the materials identified as nonmetals.

Triple-Additive Strategy for Enhanced Material and Device Stability in Perovskite Solar Cells.

The stability of the FAPbI perovskite phase is significantly affected by internal strain. In this report, additives in the perovskite precursor solution are designed to prevent local lattice mismatch of the resulting perovskite layer. Instead of using a conventional methylammonium chloride (Control), triple additives (Target) are introduced by considering ion association and formation energy.

Transcorrelated methods applied to second row elements.

We explore the applicability of the transcorrelated method to the elements in the second row of the periodic table. We use transcorrelated Hamiltonians in conjunction with full configuration interaction quantum Monte Carlo and coupled cluster techniques to obtain total energies and ionization potentials, investigating their dependence on the nature and size of the basis sets used. Transcorrelation accelerates convergence to the complete basis set limit relative to conventional approaches, and chemically accurate results can generally be obtained with the cc-pVTZ basis, even with a frozen Ne core in the post-Hartree-Fock treatment.

Pyrrolation of Melem: A Facile Gateway into the Field of Monomeric s-Heptazine Chemistry.

Monomeric s-heptazines are an intriguing class of compounds with many attractive properties for various areas of application such as photocatalysis or organic light-emitting diodes. However, research into these properties has so far been challenging, as only a few synthetic routes for the preparation of monomeric s-heptazines are known in the literature. Furthermore, these few reported synthetic pathways generally require the use of specialized equipment that may not be available to all laboratories interested in studying monomeric s-heptazines.

Thermal diffuse scattering analysis of AgO binary system via X-ray powder diffraction.

Diffuse scattering is a component of the powder pattern bearing information on the local atomic structure and disorder of crystalline materials. It is visible in the X-ray diffraction patterns of binary structures like AgO, which has a large mean squared displacement for its constituent elements. Pair distribution function (PDF) analysis is widely employed to extract this local structural information, embedded in the widths of PDF peaks.

The Devil Is in the Details: Pitfalls and Ambiguities in the Analysis of X-ray Powder Diffraction Data of 2D Covalent Organic Frameworks.

X-ray powder diffraction (XRPD) data of covalent organic frameworks (COFs) seem to be simple and apparently do not contain a lot of structural information, as these patterns usually do not show more than 3-5 distinguishable Bragg peaks. As COFs are inherently complex materials exhibiting a variety of disorder phenomena like stacking faults, layer curving, or disordered solvent molecules populating the pores, the interpretation of XRPD patterns is far from being trivial. Here we emphasize the critical need for precision and caution in XRPD data acquisition, refinement, and interpretation to avoid common pitfalls and overinterpretations in data analysis.

Negative gas adsorption transitions and pressure amplification phenomena in porous frameworks.

Nanoporous solids offer a wide range of functionalities for industrial, environmental, and energy applications. However, only a limited number of porous materials are responsive, the nanopore dynamically alters its size and shape in response to external stimuli such as temperature, pressure, light or the presence of specific molecular stimuli adsorbed inside the voids deforming the framework. Adsorption-induced structural deformation of porous solids can result in unique counterintuitive phenomena.

Nanoscale Mapping of Magnetic Auto-Oscillations with a Single Spin Sensor.

Spin Hall nano-oscillators convert DC to magnetic auto-oscillations in the microwave regime. Current research on these devices is dedicated to creating next-generation energy-efficient hardware for communication technologies. Despite intensive research on magnetic auto-oscillations within the past decade, the nanoscale mapping of those dynamics remained a challenge.

Solvothermal Template-Induced Hierarchical Porosity in Covalent Organic Frameworks: A Pathway to Enhanced Diffusivity.

The rapid advancement of covalent organic frameworks (COFs) in recent years has firmly established them as a new class of molecularly precise and highly tuneable porous materials. However, compared to other porous materials, such as zeolites and metal-organic frameworks, the successful integration of hierarchical porosity into COFs remains largely unexplored. The challenge lies in identifying appropriate synthetic methods to introduce secondary pores without compromising the intrinsic structural porosity of COFs.

FCIQMC-CASPT2 with Imaginary-Time-Averaged Wave Functions.

A new method to perform complete active space second-order perturbation theory on top of large active spaces optimized with full configuration quantum Monte Carlo is presented. Computing the three- and Fock-contracted four-particle density matrix from imaginary-time-averaged wave functions is found to resolve fermionic positivity violations and to ensure numerical stability. The protocol is applied to [NiFe]-hydrogenase, [CuO]-oxidase and Fe-porphyrin model systems up to 26 electrons in 27 orbitals and benchmarked against DMRG-CASPT2.