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Abstract The layered material α-RuCl3 is a promising candidate to realize the Kitaev quantum spin liquid (QSL) state. However, at ambient pressure, deviations from the perfect Kitaev geometry prevent the existence of the QSL state at low temperatures. Here we present the discovery of a pressure-induced high-symmetry phase in α-RuCl3, which creates close to ideal conditions for the emergence of a QSL. Employing a novel approach based on Bragg and diffuse scattering of synchrotron radiation, we reveal a pressure-induced reorganization of the RuCl3-layers. Most importantly, this reorganization affects the structure of the layers themselves, which acquire a high trigonal symmetry. For this trigonal phase the largest ratio between the Kitaev (K) and the Heisenberg exchange (J) ever encountered is found: K/J = 124. Additionally, we demonstrate that this phase can also be stabilized by a slight biaxial pressure. This not only resolves the conflicting reports of low-temperature structures in the literature, but also facilitates the investigation of the high-symmetry phase and its potential QSL using a range of experimental techniques.

Abstract Low-temperature neutron diffraction experiments at $$P= 8$$ P = 8 GPa have been conducted to investigate the magnetic structures of metallic Holmium at high pressures by employing a long d-spacing high-flux diffractometer and a Paris-Edinburgh press cell inside a cryostat. We find that at $$P=8$$ P = 8 GPa and $$T=5$$ T = 5 K, no nuclear symmetry change is observed, keeping therefore the hexagonal closed packed (hcp) symmetry at high pressure. Our neutron diffraction data confirm that the ferromagnetic state does not exist. The magnetic structure corresponding to the helimagnetic order, which survives down to 5 K, is fully described by the magnetic superspace group formalism. These results are consistent with those previously published using magnetization experiments.

The development of highly luminescent materials such as large Stokes shift fast emitters is desirable for their potential application in photonics. Here the authors engineer hetero-ligand metal-organic frameworks nanoparticles to achieve high emission yield, large Stokes shift and realize a prototypal fast scintillator.

Introduction Aging is a demographic global trend and a challenge for public mental health; however, gaps persist for a comprehensive definition of mental health, risk, protective factors, and processes involved, which represent a greater problem in middle-income countries, where evidence is scarce. Objectives To identify combined mental health profiles in older adults, based on self-report of anxiety symptoms, depressive symptoms, and perception of well-being, and to identify risk and protective variables for each of the groups, based on a sample of older adults attending primary health care (PHC) centers in the Province of Concepción, Chile. Methods A convenience sample of 573 adults of both sexes, over 65 years, autonomous, attending PHC centers in the Province of Concepción, Chile, answered a set of instruments assessing anxiety symptoms (SCL-90), depressive symptoms (PHQ-9) and perception of well-being (Pemberton Happiness Index) and eventually associated variables that included sociodemographic and living arrangements, social participation, threatening life events (LTE), loneliness (ULS-3), and social support (MSPSS). Latent profile mixture analysis was used to identify groups of adults with similar mental health, and pertinence in each group was explained using random forests. The relationship between predictors and latent profiles were analyzed with multinomial regression. Results A solution of 4 groups with distinctive mental health profiles was determined: Group 1 (28%) with high depressive symptoms, high anxiety, and low well-being; Group 2 (32%) with moderate depressive symptoms, high anxiety and moderate well-being; Group 3 (24%) with moderate depressive symptoms, low anxiety and moderate well-being and; Group 4 (15%) characterized by individuals with low anxious or depressive symptoms, high well-being, and absence of mental disorder. Using random forests, this model predicts 63% variance between groups. A large number of variables were found to significantly predict membership in one of the 4 groups. Specifically: gender, satisfaction with living arrangement, economic crisis, own disease, and death or illness of friend, perception of general health, intimate, relational and collective loneliness, social support from family and significant others, and social support from friends. Conclusions The 4-group classification is a parsimonious solution where group 1 characterize people with poor mental health; groups 2 and 3 languishing with high and low anxiety respectively; and group 4 healthy and flourishing. Overall, these groups highlight the role of close interpersonal relationships or primary ties, both in terms of intimacy versus loneliness/isolation and in satisfaction with living arrangements for the elderly. The importance of these psychosocial predictors on combined mental health in the elderly further the need to understand their role and mechanisms to design promotion and prevention strategies. Disclosure of Interest None Declared

Abstract The 5d transition metals have attracted specific interest for high-pressure studies due to their extraordinary stability and intriguing electronic properties. In particular, iridium metal has been proposed to exhibit a recently discovered pressure-induced electronic transition, the so-called core-level crossing transition at the lowest pressure among all the 5d transition metals. Here, we report an experimental structural characterization of iridium by x-ray probes sensitive to both long- and short-range order in matter. Synchrotron-based powder x-ray diffraction results highlight a large stability range (up to 1.4 Mbar) of the low-pressure phase. The compressibility behaviour was characterized by an accurate determination of the pressure-volume equation of state, with a bulk modulus of 339(3) GPa and its derivative of 5.3(1). X-ray absorption spectroscopy, which probes the local structure and the empty density of electronic states above the Fermi level, was also utilized. The remarkable agreement observed between experimental and calculated spectra validates the reliability of theoretical predictions of the pressure dependence of the electronic structure of iridium in the studied interval of compressions.

Cellulose and cyclodextrins possess unique properties that can be tailored, combined, and used in a considerable number of applications, including textiles, coatings, sensors, and drug delivery systems. Successfully structuring and applying cellulose and cyclodextrins conjugates requires a deep understanding of the relation between structural, and soft matter behavior, materials, energy, and function. This review focuses on the key advances in developing materials based on these conjugates. Relevant aspects regarding structural variations, methods of synthesis, processing and functionalization, and corresponding supramolecular properties are presented. The use of cellulose/cyclodextrin conjugates as intelligent platforms for applications in materials science and pharmaceutical technology is also outlined, focusing on drug delivery, textiles, and sensors.