Adaptation of the BaAl Type to Small Cations: The Case of NaGa.

Single-phase NaGa samples were prepared by annealing stoichiometric element mixtures at 200 °C, 300 °C, and 450 °C in closed tantalum ampoules. No compositional homogeneity range was detected. While single crystals annealed at 200 °C feature a fully ordered crystal structure, a crystal annealed at 300 °C reveals a defect with mutual exchange of Na atoms and Ga dumbbells.

Nitridochromate(IV) fluoride - LiCa[CrN]NF.

LiCa[CrN]NF ( (#58), = 17.5230(13) Å, = 7.3379(5) Å, = 4.

Ordering by cation replacement in the system NaLiGa.

Samples of the pseudo-binary system NaLiGa ( ≤ 1) were synthesized from the elements at 300 °C in sealed Ta ampoules or by the reaction of NaGa with LiCl. The peritectic formation temperature decreases with increasing Li content from 501(2) °C ( = 0) to 489(2) °C ( = 1). The boundary compositions NaGa and NaLiGa crystallize with different structure types related by a group-subgroup relation.

Charge Transfer in Be-Ru Compounds.

During the investigation of the binary system Be-Ru two new phases - Be Ru and Be Ru - with similar compositions (63.6 at. % Be and 63.

Nitridochromate(IV): LiSr[CrN].

The quaternary nitridochromate(IV) LiSr[CrN] crystallizes in a new structure type with the non-centrosymmetric space group 2 (no. 4) with = 5.5685(7) Å, = 5.

Chemical and Physical Properties of YHg and LuHg.

Amalgams have played an important role in fundamental and applied solid-state chemistry and physics because of the diversity of crystallographic features and properties that they have to offer. Moreover, their peculiar chemical properties can sometimes give rise to unconventional superconducting or magnetic ground states. In the current work, we present an in-depth analysis of single crystals of YHg and LuHg (MgCd structure type, space group 6/).

NaGa: A Zintl-Wade Phase Related to "α-Tetragonal Boron".

NaGa crystallizes with the orthorhombic space group (no. 62; = 14.8580(6) Å, = 8.

The crystal structure of quaternary (Sn,Pb,Bi)Pt.

Quaternary (Sn,Pb,Bi)Pt was synthesized by melting of the elements in an evacuated silica glass ampoule. The crystal structure was established by single-crystal X-ray diffraction and adopts an atomic arrangement of the NiAs type with additional occupation of the voids. Decisive for the refinement was the composition of the crystals as determined by energy dispersive X-ray spectroscopy (EDXS), resulting in a formula of (SnPbBi)Pt.

Ge Co : Creating "Empty" Space by High Pressure.

The compound Ge Co (x=0.54(6), a=10.9861(3) Å, space group Im m) prepared under high pressure and at high temperature is metastable under ambient conditions.

The First Alkaline-Earth Azidoaurate(III), Ba[Au(N ) ] ⋅ 4 H O.

Transparent, dark orange Ba[Au(N ) ]  ⋅ 4 H O was synthesized by reaction of Ba(N ) and AuCl or HAuCl in aqueous solution. The novel barium tetraazidoaurate(III) tetrahydrate crystallizes in the monoclinic space group Cc (no. 9) with a=1813.

Crystal Chemistry and Physics of UCd.

In the phase diagram U-Cd, only one compound has been identified so far─UCd (space group 3̅). Since the discovery of this material, the physical properties of UCd have attracted a considerable amount of attention. In particular, its complex magnetic phase diagram─as a result of tuning with magnetic field or pressure─is not well-understood.

MgPt: Chemical Bonding Inhomogeneity and Structural Complexity.

MgPt represents the family of complex intermetallic compounds (complex metallic alloys, CMAs). It crystallizes in the cubic non-centrosymmetric space group 4̅3 with = 20.1068(2) Å and around 400 atoms in a predominantly ordered arrangement.

Superconductivity in Crystallographically Disordered LaHg.

The influence of structural disorder on superconductivity is not yet fully understood. A concurrent examination of crystallographic and physical properties of LaHg reveals that this material enters a superconducting state below = 2.4 K while showing crystallographic disorder in one dimension.

A Borosilicide with Clathrate VIII Structure.

The high-pressure phase NaBSi (3 < < 5) is the first representative of a borosilicide crystallizing in the rarely occurring clathrate VIII type structure. Crystals with composition NaBSi (space group 43̅; = 9.7187(2) Å; Pearson symbol 54) were obtained at 5-8 GPa and 1200 K.

Non-innocent cyanido ligands: tetracyanidoferrate(-II) as carbonyl copycat.

While a negative oxidation state occurs rarely for metals in general, this is commonly known for metal carbonyl anions, carbonyl metalates. Although CO and CN are isoelectronic, cyanidometalates usually do not exhibit metal centers with negative oxidation states. However, we report on the electron-rich tetrahedral tetracyanidoferrate(-II) anion [Fe(CN)], which was stabilized in (SrN)[Fe(CN)] (space group 3, = 702.

Polycation-Polyanion Architecture of the Intermetallic Compound MgGaIr.

MgGaIr ( = 0.05) was synthesized by direct reaction of the elements in welded tantalum containers at 1200 °C and subsequent annealing at 500 °C for 30 days. Its crystal structure represents a new prototype and was determined by single-crystal technique as follows: space group 6/, Pearson symbol 90, = 18, = 14.

MgPt: Anionic Chains in a EuGa-Type Structure.

The binary phase MgPt was prepared by direct reaction between the elements or by spark-plasma synthesis starting with MgH and PtCl. The compound crystallizes in the monoclinic space group 2/ with = 7.2096(3) Å, = 7.

Tricyanidoferrates(-IV) and Ruthenates(-IV) with Non-Innocent Cyanido Ligands.

Exceptionally electron-rich, nearly trigonal-planar tricyanidometalate anions [Fe(CN) ] and [Ru(CN) ] were stabilized in LiSr [Fe(CN) ] and AE [M(CN) ] (AE=Sr, Ba; M=Fe, Ru). They are the first examples of group 8 elements with the oxidation state of -IV. Microcrystalline powders were obtained by a solid-state route, single crystals from alkali metal flux.

"Excess" electrons in LuGe.

The monogermanide LuGe is obtained via high-pressure high-temperature synthesis (5-15 GPa, 1023-1423 K). The crystal structure is solved from single-crystal X-ray diffraction data (structure type FeB, space group Pnma, a=7.660(2) Å, b=3.

Crystal Structure and Physical Properties of the Cage Compound HfBIr.

HfBIr crystallizes with a new type of structure: space group , = 5.6300(3) Å, = 11.2599(5) Å, and = 3.

YBePt- a non-centrosymmetric cage superconductor with multi-centre bonding in the framework.

The new ternary compound YBePt was prepared from elements by arc melting, and its crystal structure was determined from single-crystal X-ray diffraction data (space group I4[combining macron]3d, a = 13.4849(3) Å). The material is the first representative of a new structure type of complex intermetallic compounds and reveals a cage-like crystal structure.

Preparation of cobalt borides by solid-gas reactions.

The reaction of Co with gaseous BBr3 in a temperature range of 700 to 1000 °C was studied using the hot-wire method with an experimental set-up reminiscent of the van Arkel-de Boer method. The borides Co2B und CoB form as layers on the surface of elemental cobalt. The influence of pressure, temperature and time on the reaction rate and on the composition of the borides was investigated.

In-Cage Interactions in the Clathrate Superconductor Sr Si.

The clathrate I superconductor Sr Si is obtained under high-pressure high-temperature conditions, at 5 GPa and temperatures in the range of 1273 to 1373 K. At ambient pressure, the compound decomposes upon heating at T=796(5) K into Si and SrSi . The crystal structure of the clathrate is isotypic to that of Na Si .