AEuAsS3 (A = Li, K, Rb, and Cs): New As3+ Species from an Arsenic-Rich Polysulfide Flux

Nanotube Structure of AsPS4-xSex (x = 0, 1)

Single-wall nanotubes of isostructural AsPS4-xSex (x = 0, 1) are grown from solid-state reaction of stoichiometric amounts of the elements. The structure of AsPS4 was determined using single-crystal X-ray diffraction and refined in space group P 1 ¯ . The infinite, single-walled AsPS4 nanotubes have an outer diameter of ≈1.1 nm and are built of corner-sharing PS4 tetrahedra and AsS3 trigonal pyramids. Each nanotube is nearly hexagonal, but the ≈3.4 Å distance between S atoms on adjacent nanotubes allows them to easily slide past one another, resulting in the loss of long-range order. Substituting S with Se disrupted the crystallization of the nanotubes, resulting in amorphous products that precluded the determination of the structure for AsPS3Se. 31P solid-state NMR spectroscopy indicated a single unique tetrahedral P environment in AsPS4 and five different P environments all with different degrees of Se substitution in AsPS3Se. Optical absorption spectroscopy revealed an energy band gap of 2.7 to 2.4 eV for AsPS4 and AsPS3Se, respectively. Individual AsPS4 microfibers showed a bulk conductivity of 3.2 × 10-6 S/cm and a negative photoconductivity effect under the illumination of light (3.06 eV) in ambient conditions. Thus, intrinsic conductivity originates from hopping through empty trap states along the length of the AsPS4 nanotubes.

LiSrSbS3: parallel configurations of lone pair electrons inducing a large birefringence

Enhancement of birefringence is significant since the birefringent materials can create and control polarized light and be used extensively in various advanced optical systems. By optimizing the arrangement of [SbS₃] units with stereo-chemical active lone pair electrons, a new quaternary thioantimonate LiSrSbS₃ with a large birefringence has been successfully synthesized by a high temperature solid-state reaction method. LiSrSbS₃ crystallizes in the monoclinic space group of P2₁/c. In the structure, the isolated infinite [LiS₄] chains and zigzag [SrS₆] chains are alternately connected with each other to compose a three-dimensional (3D) framework, and the isolated pyramid [SbS₃] units are located between them. To analyze the source of large birefringence, the electronic structure and optical properties of LiSrSbS₃ were further investigated by the first-principles method, and the results show that the optimized arrangement [SbS₃] trigonal pyramid induces a large birefringence.

A unique dysprosium selenoarsenate(iii) exhibiting a photocurrent response and slow magnetic relaxation behavior

A unique dysprosium selenoarsenate(iii) contains large oligomeric cluster [As₃Se₆]³⁻anions with binuclear dysprosium complexes as counterions, and exhibits a photocurrent response and slow magnetic relaxation behavior.

A series of new lanthanoid thioarsenates: insights into the influence of lanthanide contraction on the formation of new lanthanoid thioarsenates

A series of new lanthanoid thioarsenates were prepared and they would be helpful for gaining insights into the influence of lanthanide contraction on the formation of other new lanthanoid thioarsenates.