Superionic Conduction in the Plastic Crystal Polymorph of NaPS.

Sodium thiophosphates are promising materials for large-scale energy storage applications benefiting from high ionic conductivities and the geopolitical abundance of the elements. A representative of this class is NaPS, which currently shows two known polymorphs-α and β. This work describes a third polymorph of NaPS, γ, that forms above 580 °C, exhibits fast-ion conduction with low activation energy, and is mechanically soft.

Structural Stability Diagram of ALnPS Compounds (A = Na, K, Rb, Cs; Ln = Lanthanide).

Thiophosphate compounds have been studied extensively in the past for their rich structural variations and for a large variety of interesting properties. Here, we report 11 new phases with the composition ALnPS (A = Na, K, Rb, Cs; Ln = lanthanide). These new thiophosphates crystallize in four different structure types, with the space groups Fdd2, P1̅, P2, and P2/c, respectively.

Copper Selenidophosphates Cu4P2Se6, Cu4P3Se4, Cu4P4Se3, and CuP2Se, Featuring Zero-, One-, and Two-Dimensional Anions.

Five new compounds in the Cu/P/Se phase diagram have been synthesized, and their crystal structures have been determined. The crystal structures of these compounds comprise four previously unreported zero-, one-, and two-dimensional selenidophosphate anions containing low-valent phosphorus. In addition to two new modifications of Cu4P2Se6 featuring the well-known hexaselenidohypodiphosphate(IV) ion, there are three copper selenidophosphates with low-valent P: Cu4P3Se4 contains two different new anions, (i) a monomeric (zero-dimensional) selenidophosphate anion [P2Se4](4-) and (ii) a one-dimensional selenidophosphate anion [Formula: see text], which is related to the well-known gray-Se-like [Formula: see text] Zintl anion.

Touchless Optical Finger Motion Tracking Based on 2D Nanosheets with Giant Moisture Responsiveness.

A new optical touchless positioning interface based on ultrasensitive humidity responsive 1D photonic crystals utilizing the giant moisture dependent swelling capacity of 2D phosphatoantimonate nanosheets is presented. The spatially confined, full spectral color change combined with reversible transparency switching induced by the humidity sheath of a human finger allows for real time, true color lateral finger motion tracking under touchless conditions.