Bose-Einstein condensation of a two-magnon bound state in a spin-1 triangular lattice.

In ordered magnets, the elementary excitations are spin waves (magnons), which obey Bose-Einstein statistics. Similarly to Cooper pairs in superconductors, magnons can be paired into bound states under attractive interactions. The Zeeman coupling to a magnetic field is able to tune the particle density through a quantum critical point, beyond which a 'hidden order' is predicted to exist.

A rare case of a zero-field single-ion magnet in a cerium(III) pseudo-icosahedral complex.

The synthesis and structural characterisation of [Ln(Tp)]I (1-Ln; Ln = La, Ce, Pr, Nd) (Tp = hydrotris(3-(2'-furyl)-pyrazol-1-yl)borate) have been reported as an isomorphous series adopting pseudo-icosahedral ligand field geometries. Continuous shape measurement (CShM) analyses on the crystal field environments of 1-Ln show the smallest values yet reported for complexes employing two hexadentate ligands (-scorpionate environments), with the smallest belonging to 1-La. Single-ion magnetism for 1-Ce, 1-Pr and 1-Nd was probed with ac magnetic susceptibility studies revealing slow magnetic relaxation for 1-Nd in applied magnetic fields and in zero-applied field for 1-Ce, which is a rare observation for Ce(III)-based single-ion magnets.

Carbon Adsorbent Properties Impact Hydrated Electron Activity and Perfluorocarboxylic Acid (PFCA) Destruction.

Carbon-based adsorbents used to remove recalcitrant water contaminants, including perfluoroalkyl substances (PFAS), are often regenerated using energy-intensive treatments that can form harmful byproducts. We explore mechanisms for sorbent regeneration using hydrated electrons (e ) from sulfite ultraviolet photolysis (UV/sulfite) in water. We studied the UV/sulfite treatment on three carbon-based sorbents with varying material properties: granular activated carbon (GAC), carbon nanotubes (CNTs), and polyethylenimine-modified lignin (lignin).

Born This Way? National Collective Narcissism, Implicit Homophobia, and Homosexual Essentialism in Populist Poland.

Prejudice toward the LGBT community has become prevalent in Poland under the ultraconservative populist government. The results of three studies conducted between 2018 and 2019 (N = 879, N = 324, and N = 374) indicate that Polish collective narcissism-the belief that the exaggerated greatness of the nation is not recognized by others-is associated with implicit homophobia assessed as the intuitive disapproval of gay men and automatic evaluative preference of heterosexuality over homosexuality. Those associations were to a large extent explained by the relationships between collective narcissism and (1) the belief that groups defined by sexual orientations are essentially distinct; (2) the belief that homosexuality is a personal choice, not genetically determined or culturally universal.

Groundwater solutes influence the adsorption of short-chain perfluoroalkyl acids (PFAA) to colloidal activated carbon and impact performance for in situ groundwater remediation.

Subsurface injection of colloidal activated carbon (CAC) is an in situ remediation strategy for perfluoroalkyl acids (PFAA), but the influence of groundwater solutes on longevity is uncertain, particularly for short-chain PFAA. We quantify the impact of inorganic anions, dissolved organic matter (DOM), and stabilizing polymer on PFAA adsorption to a commercial CAC. Surface characterization supported PFAA chain-length dependent adsorption results and mechanisms are provided.

Position-Dependent Segmental Relaxation in Bottlebrush Polymers.

Segmental dynamics of specifically labeled poly(propylene oxide), PPO, based bottlebrush polymers, PNB--PPO, were studied using quasi-elastic neutron scattering. The focus was set to different parts of the side chains to investigate the hypothetical gradual relaxation behavior within the side chains of a bottlebrush polymer. Different sections of the side chains were highlighted for QENS via sequential polymerization of protonated and deuterated monomers to allow the study of the relaxation behavior of the inner and outer parts of the side chain separately.

-based determination of lanthanoid-radical exchange as visualised by inelastic neutron scattering.

Magnetic exchange coupling can modulate the slow magnetic relaxation in single-molecule magnets. Despite this, elucidation of exchange coupling remains a significant challenge for the lanthanoid(iii) ions, both experimentally and computationally. In this work, the crystal field splitting and 4f-π exchange coupling in the erbium-semiquinonate complex [ErTpdbsq] (Er-dbsq; Tp = hydro-tris(1-pyrazolyl)borate, dbsqH = 3,5-di--butyl-1,2-semiquinone) have been determined by inelastic neutron scattering (INS), magnetometry, and CASSCF-SO calculations.

Competing itinerant and local spin interactions in kagome metal FeGe.

The combination of a geometrically frustrated lattice, and similar energy scales between degrees of freedom endows two-dimensional Kagome metals with a rich array of quantum phases and renders them ideal for studying strong electron correlations and band topology. The Kagome metal, FeGe is a noted example of this, exhibiting A-type collinear antiferromagnetic (AFM) order at T ≈ 400 K, then establishes a charge density wave (CDW) phase coupled with AFM ordered moment below T ≈ 110 K, and finally forms a c-axis double cone AFM structure around T ≈ 60 K. Here we use neutron scattering to demonstrate the presence of gapless incommensurate spin excitations associated with the double cone AFM structure of FeGe at temperatures well above T and T that merge into gapped commensurate spin waves from the A-type AFM order.

Operationalizing anthropological theory: four techniques to simplify networks of co-occurring ethnographic codes.

The use of data and algorithms in the social sciences allows for exciting progress, but also poses epistemological challenges. Operations that appear innocent and purely technical may profoundly influence final results. Researchers working with data can make their process less arbitrary and more accountable by making theoretically grounded methodological choices.

Thermal batteries based on inverse barocaloric effects.

To harvest and reuse low-temperature waste heat, we propose and realize an emergent concept-barocaloric thermal batteries based on the large inverse barocaloric effect of ammonium thiocyanate (NHSCN). Thermal charging is initialized upon pressurization through an order-to-disorder phase transition, and the discharging of 43 J g takes place at depressurization, which is 11 times more than the input mechanical energy. The thermodynamic equilibrium nature of the pressure-restrained heat-carrying phase guarantees stable long-duration storage.

A colossal barocaloric effect induced by the creation of a high-pressure phase.

As a promising environment-friendly alternative to current vapor-compression refrigeration, solid-state refrigeration based on the barocaloric effect has been attracting worldwide attention. Generally, both phases in which a barocaloric effect occurs are present at ambient pressure. Here, instead, we demonstrate that KPF exhibits a colossal barocaloric effect due to the creation of a high-pressure rhombohedral phase.

Inelastic Neutron Scattering Measurement of the Ground State Tunneling Gap in Tb and Ho Analogues of a Dy Field-Induced Single-Molecule Magnet.

Recent advances in single-molecule magnet (SMM) research have placed great value on interpretation of inelastic neutron scattering (INS) data for rare earth (RE)-containing SMMs. Here, we present the synthesis of several rare earth complexes where combined magnetic and INS studies have been performed, supported by calculations. The reaction of rare earth nitrate salts with 2,2'-bipyridine (2,2'-bpy) and tetrahalocatecholate (XCat, X = Br, Cl) ligands in methanol (MeOH) afforded two new families of compounds [RE(2,2'-bpy)(XCat)(XCatH)(MeOH)] (X = Br and RE = Y, Eu, Gd, Tb, Dy, Ho, Yb for ; X = Cl and RE = Y, Tb, Dy, Ho, and Yb for ).

Side Chain Dynamics of Poly(norbornene)-g-Poly(propylene oxide) Bottlebrush Polymers.

The segmental dynamics of the side chains of poly(norbornene)-g-poly(propylene oxide) (PNB-g-PPO) bottlebrush polymer in comparison to PPO is studied by quasi-elastic neutron scattering. Having experimental time and length scale information simultaneously allows to extract spatial information in addition to relaxation time. Tethering one end of the PPO side chain onto a stiff PNB backbone slows down the segmental relaxation, over the length and time scales investigated.

Two-dimensional quantum universality in the spin-1/2 triangular-lattice quantum antiferromagnet NaBaCo(PO).

An interplay of geometrical frustration and strong quantum fluctuations in a spin-1/2 triangular-lattice antiferromagnet (TAF) can lead to exotic quantum states. Here, we report the neutron-scattering, magnetization, specific heat, and magnetocaloric studies of the recently discovered spin-1/2 TAF NaBaCo(PO), which can be described by a spin-1/2 easy axis XXZ model. The zero-field neutron diffraction experiment reveals an incommensurate antiferromagnetic ground state with a significantly reduced ordered moment of about 0.

An inelastic neutron scattering investigation of holmium orthoferrite.

The inelastic neutron scattering spectra recorded in this study and elsewhere provide a useful set of crystal-field (CF) energy levels for the ground= 6 term of Hoin HoFeO. The resolution of the low-energy, temperature-dependent pseudo-quadrupole ground state splitting and magnon peaks is consistent with the self-ordering of the Hosublattice at∼ 8-10 K and supports earlier electron spin resonance investigations of the Homagnon behaviour. Systematic analysis of the grouped singlet CF levels of Ho: HoFeO, in conjunction with the CF Kramers doublet levels of the neighbouring Er: ErFeO, has yielded possible sets of CF parameters for the two systems.

Modulation of Slow Magnetic Relaxation in Gd(III)-Tetrahalosemiquinonate Complexes.

Incorporating lanthanoid(III)-radical magnetic exchange coupling is a possible route to improving the performance of lanthanoid (Ln) single-molecule magnets (SMMs), molecular materials that exhibit slow relaxation and low temperature quantum tunnelling of the magnetization. Complexes of Gd(III) can conveniently be used as model systems to study the Ln-radical exchange coupling, thanks to the absence of the orbital angular momentum that is present for many Ln(III) ions. Two new Gd(III)-radical compounds of formula [Gd(18-c-6)X SQ(NO )].

Anomalous Structural Evolution and Glassy Lattice in Mixed-Halide Hybrid Perovskites.

Hybrid halide perovskites have emerged as highly promising photovoltaic materials because of their exceptional optoelectronic properties, which are often optimized via compositional engineering like mixing halides. It is well established that hybrid perovskites undergo a series of structural phase transitions as temperature varies. In this work, the authors find that phase transitions are substantially suppressed in mixed-halide hybrid perovskite single crystals of MAPbI Br (MA = CH NH and x = 1 or 2) using a complementary suite of diffraction and spectroscopic techniques.

Universality of Time-Temperature Scaling Observed by Neutron Spectroscopy on Bottlebrush Polymers.

The understanding of materials requires access to the dynamics over many orders of magnitude in time; however, single analytical techniques are restricted in their respective time ranges. Assuming a functional relationship between time and temperature is one viable tool to overcome these limits. Despite its frequent usage, a breakdown of this assertion at the glass-transition temperature is common.

Short-Time Dynamics of PDMS--PDMS Bottlebrush Polymer Melts Investigated by Quasi-Elastic Neutron Scattering.

We have studied the short-time dynamical behavior of polydimethylsiloxane (PDMS) bottlebrush polymers, PDMS--PDMS. The samples have similar backbone lengths but different side-chain lengths, resulting in a shape transition. Quasi-elastic neutron scattering was used to observe the dynamical changes inherent to these structural changes.

Gapless spin liquid in a square-kagome lattice antiferromagnet.

Observation of a quantum spin liquid (QSL) state is one of the most important goals in condensed-matter physics, as well as the development of new spintronic devices that support next-generation industries. The QSL in two dimensional quantum spin systems is expected to be due to geometrical magnetic frustration, and thus a kagome-based lattice is the most probable playground for QSL. Here, we report the first experimental results of the QSL state on a square-kagome quantum antiferromagnet, KCuAlBiO(SO)Cl.