Tuning of Photoluminescence by Cation Nanosegregation in the (CaMg)_<i>x</i>(NaSc)_1–<i>x</i>Si₂O₆ Solid Solution

Controlled photoluminescence tuning is important for the optimization and modification of phosphor materials. Herein we report an isostructural solid solution of (CaMg)_<i>x</i>(NaSc)_1–<i>x</i>Si₂O₆ (0 < <i>x</i> < 1) in which cation nanosegregation leads to the presence of two dilute Eu²⁺ centers. The distinct nanodomains of isostructural (CaMg)­Si₂O₆ and (NaSc)­Si₂O₆ contain a proportional number of Eu²⁺ ions with unique, independent spectroscopic signatures. Density functional theory calculations provided a theoretical understanding of the nanosegregation and indicated that the homogeneous solid solution is energetically unstable. It is shown that nanosegregation allows predictive control of color rendering and therefore provides a new method of phosphor development

Real-Space Observation of Nonvolatile Zero-Field Biskyrmion Lattice Generation in MnNiGa Magnet

Magnetic skyrmions, particular those without the support of external magnetic fields over a wide temperature region, are promising as alternative spintronic units to overcome the fundamental size limitation of conventional magnetic bits. In this study, we use in situ Lorentz microscope to directly demonstrate the generation and sustainability of robust biskyrmion lattice at zero magnetic field over a wide temperature range of 16–338 K in MnNiGa alloy. This procedure includes a simple field-cooling manipulation from 360 K (higher than Curie temperature <i>T</i>_C ∼ 350 K), where topological transition easily occurs by adapting the short-range magnetic clusters under a certain magnetic field. The biskyrmion phase is favored upon cooling below <i>T</i>_C. Once they are generated, the robust high-density biskyrmions persist even after removing the external magnetic field due to the topological protection and the increased energy barrier