29664-84-4

Upstream product

• 7440-36-0 antimony 
• 7440-19-9 samarium 
• 7440-70-2 calcium 
• 7440-69-9 bismuth 
• 7439-95-4 magnesium 

Relevant academic research and scientific papers

Valence states of rare-earth ions in RERuSn3 (RE=La, Ce, Pr, Nd, Sm) and related compounds studied by core-level photoemission spectroscopy

We have measured the 3d and 4d core-level X-ray photoelectron spectra of rare earths in RERuSn3 (RE=La, Ce, Pr, Nd and Sm) and related rare-earth compounds. The Ce 3d spectra of CeRuSnx, (x=2.85, 3.0 and 3.15) show the common feature

Structure and bonding of Bi4Ir: A difficult-to-access bismuth iridide with a unique framework structure

Crystals of Bi4Ir, a new intermetallic compound, were obtained by the reaction of an iridium-containing intermetallic precursor with liquid bismuth. X-ray diffraction on a single crystal revealed a rhombohedral structure [R3m, a = 2656.7(2) pm, and c = 701.6(4) pm]. Bi4Ir is not isostructural to Bi4Rh but combines motifs of the metastable superconductor Bi14Rh3 with those found in the weak topological insulator Bi14Rh3I9. The two crystallographically independent iridium sites in Bi4Ir have square-prismatic and skewed-square-antiprismatic bismuth coordination with Bi-Ir distances of 283-287 pm. By sharing common edges, the two types of [IrBi8] units constitute a complex three-dimensional network of rings and helices. The bonding in the heterometallic framework is dominated by pairwise Bi-Ir interactions. In addition, three-center bonds are found in the bismuth triangles formed by adjacent [IrBi8] polyhedra. Density functional theory based band-structure calculations suggest metallic properties.

Phase equilibria in the Sm-Zr-Sb system at 1070 K

Phase equilibria in the Sm-Zr-Sb system were investigated using x ray powder diffraction and metallographic analysis. The alloys were made in an electric arc furnace under an argon atmosphere using non-consumable tungsten electrode and a water-cooled tray. It was found that the system contained extended regions of solid solutions for SmSb. The results obtained were used in the construction of the isothermal cross-section of the Sm-Zr-Sb system at 1070 K.

A metallic room-temperature oxide ion conductor

Nanoparticles of Bi3Ir, obtained from a microwave-assisted polyol process, activate molecular oxygen from air at room temperature and reversibly intercalate it as oxide ions. The closely related structures of Bi3Ir and Bi3IrOx (x≤2) were investigated by X-ray diffraction, electron microscopy, and quantum-chemical modeling. In the topochemically formed metallic suboxide, the intermetallic building units are fully preserved. Time- and temperature-dependent monitoring of the oxygen uptake in an oxygen-filled chamber shows that the activation energy for oxide diffusion (84meV) is one order of magnitude smaller than that in any known material. Bi3IrOx is the first metallic oxide ion conductor and also the first that operates at room temperature.

Mg5.23Sm0.77Sb4: An ordered superstructure derived from the Mg3Sb2 structure type

The ternary polar intermetallic phase Mg5.231(8)Sm 0.769(8)Sb4 has been obtained from solid-state reactions at 700-850°C in sealed Ta or Nb containers when the synthetic conditions took into account its characteristic incongruent melting point. The compound crystallizes in the trigonal space group P3 (Z = 1) with a = 4.618(1) A and c = 14.902(6) A in a structure that derives from that of Mg 3Sb2 (anti-La2O3 type). This composition appears to be near the lower limit of Sm content, and solutions with appreciably higher Sm contents are also stable [Mg6-xSm xSb4, x ≤ 1]. The result provides the first example of a superstructure of a Mg3Sb2-like structure with a doubled c axis induced by ordering a mixture of the larger divalent Sm and Mg ions separately within alternate layers of octahedral sites. Still larger proportions of Sm also give rise to a second solid solution region in the parent Mg 3Sb2 type structure (P3m1), Mg3-ySm ySb4, 0 ≤ y ≤ 1. Retention of the same 3e - valence electron counts per antimony in all of these phases suggests that the compounds remain electron precise and Zintl phases. Analogous compounds with Ca, Sr, or Ba substitution have evidently not been investigated.

Synthesis and Transport Properties of the Family of Zintl Phases Ca3RESb3(RE = La-Nd, Sm, Gd-Tm, Lu): Exploring the Roles of Crystallographic Disorder and Core 4f Electrons for Enhancing Thermoelectric Performance

Zintl phases with complex crystal structures have been studied as promising candidate materials for thermoelectric (TE) applications. Here, we report the syntheses of the family of rare-earth metal Zintl phases with the general formula Ca4-xRExSb3 (x ≈ 1; RE = La-Nd, Sm, Gd-Tm, Lu). The structural elucidation is based on refinements of single-crystal X-ray diffraction data for 12 unique chemical compositions. The cubic structure is confirmed as belonging to the anti-Th3P4 structure type (space group I4ˉ 3d, no. 220, Z = 4), where the Ca and RE atoms share the same atomic site with ca. 75 and 25% occupancies, respectively. Such crystallographic disordering of divalent Ca and trivalent RE atoms in the structure provides a pathway to intricate bonding. The latter, together with the presence of heavy elements such as Sb and the lanthanides, are expected to enhance the scattering probability of phonons, thereby leading to low thermal conductivity κ comparable to that of the ordered RE4Sb3. The drive of the hypothetical parent compound Ca4Sb3 to be stabilized by alloying with rare-earth metals can be understood following the Zintl-Klemm concept, as the resultant formula may be rationalized as (Ca2+)3RE3+(Sb3-)3, indicating the realization of closed-shell electronic configurations for all elements. This notion is confirmed by electronic structure calculations, which reveal narrow bandgaps Eg = 0.77 and 0.53 eV for Ca3LaSb3 and Ca3LuSb3, respectively. In addition, the incorporation of RE atoms into the structure drives the phase into a state of a degenerate semiconductor with dominant hole charge carriers.

Investigation of the transport properties and compositions of the Ca2RE7Pn5O5 series (RE=Pr, Sm, Gd, Dy; Pn=Sb, Bi)

The Ca2RE7Pn5O5 phases (RE=Pr, Sm, Gd, Dy; Pn=Sb, Bi) were successfully prepared from high temperature reactions at 1225–1300?°C. These phases maintain the same structure types as the parent RE9Pn5O5 phases, except for a Ca/RE mixing. The study and preparation of these phases was motivated by the desire to shift the metallic type properties of the parent RE9Pn5O5 phases to a level more suitable for thermoelectric applications. Electrical resistivity measurements performed on pure, bulk samples indicated all phases to be narrow band gap semiconductors or semimetals, supporting the charge balanced electron count of the Ca2RE7Pn5O5 composition. Unfortunately, all samples are too electrically resistive for any potential usage as thermoelectrics. Electronic band structure calculations performed on idealized RE9Pn5O5 structures revealed the presence of a pseudogap at the Fermi level, which is consistent with the observed electrical resistivity and Seebeck coefficient behavior.

New ternary La2Sb-type compounds, ScRESb (RE = La, Ce, Pr, Nd, Sm, Tb), and the oxygen stuffed variant Sc4Yb4Sb 4O

Scandium rare-earth metal antimonides, ScRESb (RE = La, Ce, Pr, Nd, Sm, Tb) were synthesized from scandium metal and binary RESb at 1770 K in tantalum ampoules. According to X-ray analyses of the crystal structures, they adopt the tetragonal ScCeSi-type of structure (space group I4/mmm, Pearson code tI12), a variant of La2Sb, with a fully ordered atom distribution. Especially in ScSmSb and ScTbSb, the scandium atoms are distorted from an ideal 4 4 net in a way to form Sc nets of squares and rhombi in order to adjust to the lattice shrinkage in the ab plane, caused by the lanthanide contraction. Finally the structure changes from La2Sb to Sc 2Sb-type (anti-PbFCl-type), when terbium is replaced by dysprosium. The respective compound with ytterbium was only found when stoichiometric amounts of oxygen were present, resulting in Sc4Yb4Sb 4O, a La2Sb-type variant stuffed with oxygen. A structure field map, based on specific geometric parameters, easily allows for distinguishing between oxygen stuffed and oxygen-free compounds. Magnetic susceptibility measurements of ScCeSb, ScPrSb, and ScNdSb indicate Curie-Weiss behavior with ferromagnetic exchange coupling underlying. The magnetic moments correspond to the expected values for RE3+. Copyright

Synthesis, crystal and electronic structures of new narrow-band-gap semiconducting antimonide oxides RE3SbO3 and RE 8Sb3-δO8, with RE = La, Sm, Gd, and Ho

In the search for high-temperature thermoelectric materials, two families of novel, narrow-band-gap semiconducting antimonide oxides with the compositions RE3SbO3 and RE8Sb3-δO 8 (RE = La, Sm, Gd, Ho) have been discovered. Their synthesis was motivated by attempts to open a band gap in the semimetallic RESb binaries through a chemical fusion of RESb and corresponding insulating RE 2O3. Temperatures of 1350 °C or higher are required to obtain these phases. Both RE3SbO3 and RE 8Sb3-δO8 adopt new monoclinic structures with the C2/m space group and feature similar REO frameworks composed of RE4O tetrahedral units. In both structures, the Sb atoms occupy the empty channels within the REO sublattice. High-purity bulk Sm and Ho samples were prepared and subjected to electrical resistivity measurements. Both the RE3SbO3 and RE8Sb 3-δO8 (RE = Sm, Ho) phases exhibit a semiconductor-type electrical behavior. While a small band gap in RE 3SbO3 results from the separation of the valence and conduction bands, a band gap in RE8Sb3-δO 8 appears to result from the Anderson localization of electrons. The relationship among the composition, crystal structures, and electrical resistivity is analyzed using electronic structure calculations.

Structural and 121Sb M?ssbauer spectroscopic investigations of the antimonide oxides REMnSbO (RE = La, Ce, Pr, Nd, Sm, Gd, Tb) and REZnSbO (RE = La, Ce, Pr)

Quaternary antimonide oxides REMnSbO (RE = La, Ce, Pr, Nd, Sm, Gd, Tb) and REZnSbO (RE = La, Ce, Pr) were synthesized from the RESb monoantimonides and MnO, respectively ZnO, in sealed tubes at 1170 K. Single crystals were obtained from NaCl/KCl salt fluxes. The ZrCuSiAs-type (space group P4/nmm) structures of LaMnSbO (a = 423.95(7), c = 955.5(27) pm, wR2 = 0.067, 247 F2), CeMnSbO (a = 420.8(1), c = 950.7(1) pm, wR2 = 0.097, 250 F2), SmMnSbO (a = 413.1(1), c = 942.3(1) pm, wR2 = 0.068, 330 F2), LaZnSbO (a = 422.67(6), c = 953.8(2) pm, wR2 = 0.052, 259 F2), and NdZnSbO (a = 415.9(1), c = 945.4(4) pm, wR2 = 0.109, 206 F2) were refined from single crystal X-ray diffractometer data. The structures consist of covalently bonded (RE3+O2-)+ and (T2+Sb 3-)- layers with weak ionic interlayer interactions. The oxygen and transition metal atoms both have tetrahedral coordination within the layers. 121Sb Mossbauer spectra of the REMnSbO and REZnSbO compounds show single antimony sites with isomer shifts close to -8 mms-1, in agreement with the antimonide character of these compounds. PrMnSbO and NdMnSbO show transferred hyperfine fields of 8 T at 4.2 K.