Are Selenides the Same as Sulfides? Structure, Spectroscopy, and Properties of Narrow-Gap Rare-Earth Semiconductors Sn(SSe) ( = La, Ce; = 0-0.8).

The ternary rare-earth sulfides SnS ( = La-Nd) and the partial solid solutions Sn(SSe) ( = La, Ce; = 0-0.8) were prepared in the form of polycrystalline samples by reaction of the elements at 900 °C and as single crystals in the presence of KBr flux. They adopt the LaSnS-type structure (orthorhombic, space group , = 2) consisting of chains of edge-sharing Sn octahedra separated by atoms.

Ahead by a Century: Discovery of Laves Phases Assisted by Machine Learning.

Laves phases form the most abundant group of intermetallic compounds, consisting of combinations of larger electropositive metals with smaller metals . Many practical applications of Laves phases depend on the ability to tune their physical properties through appropriate substitution of either the or component. Although simple geometrical and electronic factors have long been thought to control the formation of Laves phases, no single factor alone can make predictions accurately.

Structure and Optical Properties of LiAgGaSe and LiAgInSe.

Complete substitution of Li atoms for Ag atoms in AgGaSe and AgInSe was achieved, resulting in the solid solutions LiAgGaSe and LiAgInSe. The detailed crystal structures were determined by single-crystal X-ray diffraction and solid-state Li nuclear magnetic resonance spectroscopy, which confirm that Li atoms occupy unique sites and disorder only with Ag atoms. The tetragonal CuFeS-type structure (space group 4̅2) was retained within the entirety of the Ga-containing solid solution LiAgGaSe, which is noteworthy because the end-member LiGaSe normally adopts the orthorhombic β-NaFeO-type structure (space group 2).

Effect of aliovalent bismuth substitution on structure and optical properties of CsSnBr.

Aliovalent substitution of the B component in ABX metal halides has often been proposed to modify the band gap and thus the photovoltaic properties, but details about the resulting structure have remained largely unknown. Here, we examine these effects in Bi-substituted CsSnBr. Powder X-ray diffraction (XRD) and solid-state Sn, Cs and Bi nuclear magnetic resonance (NMR) spectroscopy were carried out to infer how Bi substitution changes the structure of these compounds.

Mercurial possibilities: determining site distributions in CuHgSnS using Cu, Sn, and Hg solid-state NMR spectroscopy.

Chalcogenides are an important class of materials that exhibit tailorable optoelectronic properties accessible through chemical modification. For example, the minerals kesterite, stannite, and velikite (CuSnS, where = Zn, Cd, or Hg, respectively) are a series of Group 12 transition metal tin sulfides that readily exhibit optical bandgaps spanning the Shockley-Queisser limit; however, achieving consensus on their structure (space group 4̄ 4̄2) has been difficult. This study explores the average long-range and local structure of CuHgSnS and evaluates the parallels of = Zn and Cd sister compounds using complementary X-ray diffraction and solid-state nuclear magnetic resonance (NMR) spectroscopy.

LaGaSeO: A Rare-Earth Oxyselenide Built from One-Dimensional Strips.

The oxyselenide LaGaSeO was obtained by reaction in NaCl flux. Its monoclinic crystal structure (space group /, = 21.2832(13) Å, = 11.

Anisotropic Near-Zero Thermal Expansion in REAg Ga ( RE = La-Nd, Sm, Eu, and Yb) Induced by Structural Reorganization.

In this work, we have discovered the anisotropic near-zero thermal expansion (NZTE) behavior in a family of compounds REAg Ga ( RE = La-Nd, Sm, Eu, and Yb). The compounds adopt the CeAlGa structure type and were obtained as single crystals in high yield by metal flux growth technique using gallium as active flux. Temperature-dependent single crystal X-ray diffraction suggests that all the compounds exhibit near zero thermal expansion along c direction in the temperature range of 100-450 K.

Metal Flux Growth, Structural Relations, and Physical Properties of EuCuGe and EuTIn (T = Cu and Ag).

Single crystals (SCs) of the compounds EuAgIn and EuCuGe were synthesized through the reactions run in liquid indium. EuAgIn crystallizes in the LaAl structure type [orthorhombic space group (SG) Immm] with the lattice parameters: a = 4.8370(1) Å, b = 10.