Struktur‐ und magnetochemische Untersuchungen an SrVF₅

Abstract

Durch Erhitzen eines Gemenges der binären Komponenten (5 d 850 °C) wurden Einkristalle von SrVF5 erhalten (a = 707, 2(1), b = 727, 1(1), c = 1471, 4(2) pm, β = 94, 96(1)°; Raumgruppe P21/c, Z = 8). Die Röntgen‐Strukturbestimmung bestätigte ihre helicale Kettenstruktur vom SrFeF5‐Typ, in der die über cis‐Ecken verknüpften Oktaeder beträchtlich verzerrt sind (Mittelwert V—F: 193, 7 pm). Die Verbindung ist schwach antiferromagnetisch; ein dreidimensionaler Ordnungspunkt deutet sich erst bei der tiefsten gemessenen Temperatur an (TN ≈ 2 K). Das flache Suszeptibilitätsmaximum bei 6 K wird einer niederdimensionalen Vorordnung zugeschrieben. Wie an einem Einkristall untersucht, ist das Verhalten anisotrop und spricht für Ausrichtung der Spins ungefähr längs [100], senkrecht zur Achse [010] der Ketten.

LiSr2[TaN3]F – a Single Chain Nitridotantalate

“…The distances Sr–N and Sr–F are ranging from 2.59 to 3.11 Å and are in good accordance with reported values for Sr–N and Sr–F distances (e.g. Sr 2 NbN 3 , Sr–N: 2.58–3.28 Å, SrVF 5 , Sr–F: 2.46–2.87 Å)5,21 and they correspond well with ionic radii tables of Baur , Slater and Shannon , respectively 22–24. Li + is coordinated in a tetrahedral way by two F – ions and two nitrogen atoms.…”

Struktur‐ und magnetochemische Untersuchungen an KCuGaF6

“…2005, 631, 115Ϫ121 zaac.wiley-vch.de 68(5) K abzeichnet. Es ist daher anzunehmen, daß sich die antiferromagnetisch gekoppelten Spinmomente etwa parallel zur b-Achse orientieren und jedenfalls senkrecht zu den Ketten die leichte Richtung (der bevorzugten Momenteinstellung) liegt, wie auch bei anderen Kettenverbindungen üblich [39,40].…”

22 New compounds and structures in the solid state

“…The compound is weakly antiferromagnetic and there is indication of three-dimensional ordering only at the lowest temperature measured (T N approximate to 2 K). 112 The crystal structure of Ba 58 Ga 22 F 180 O is mainly built from a deficient arrangement of edge-and corner-sharing fluorite-type [FBa 4 ] tetrahedra which give rise to the skeleton of the structure including large cavities in which are found isolated fluorine ions in tetrahedral and octahedral barium environments, isolated [F 2 Ba 6 ] bitetrahedra, isolated eight-coordinate barium ions in fluorine and a complex arrangement of isolated [GaF 6 ] octahedra and isolated [Ga 2 F 10 O] bioctahedra. 113 114 Rb 2 AlTb 3 F 16 is a mixed-valence terbium fluoride (Te III /Te IV ) that has a threedimensional framework built of (Tb 3 F 16 ) 52 layers stacked along the c axis and further linked by isolated (AlF 6 ) 32 octahedra.…”

“…113 114 Rb 2 AlTb 3 F 16 is a mixed-valence terbium fluoride (Te III /Te IV ) that has a threedimensional framework built of (Tb 3 F 16 ) 52 layers stacked along the c axis and further linked by isolated (AlF 6 ) 32 octahedra. The (Tb 3 F 16 ) 52 layers are constructed from edge-sharing (Tb 3 F 22 ) 112 units which arise from the edge sharing of three (TbF 9 ) monocapped square antiprisms. 115 The organic-inorganic hybrid [CH 3 (CH 2 ) 11 NH 3 ]SnI 3 (Fig.…”

“…In Sr 6 GaN 5 however, layers of [GaN 3 ] 62 are arranged on (001) planes and are separated by Sr atoms. 151 The quaternary nitride-hydride Ca 6 [Cr 2 N 6 ]H contains Ca 6 H octahedra with Ca-H distances of 2.649 A ˚and the ethane-like complex anion [Cr 2 N 6 ] 112 which has a short chromium-chromium bond length of 2.26 A ˚. Magnetic susceptibility measurements reveal the compound to be paramagnetic at room temperature and with a broad antiferromagnetic ordering centered around 55 K. 152 Single crystals of the isostructural compounds AE 4 [Cr 2 N 6 ] (AE ~Ca and Sr) were synthesised from the elements in a mixed sodium-gallium melt at 900 uC in sealed niobium tubes with NaN 3 as the nitrogen source.…”