Structures of Ta₃As and (Nb,Ta)₃As

Abstract

Te(OH)6.2(NH4)2HPO 4 ET Te(OH) 6. Na2HPO 4. H20 1447 poss6de un voisinage constitu6 par six atomes d'oxyg6ne appartenant ~t trois octa6dres TeO 6 et par la mol6cule d 'eau O(w).L'atome Na(2) est entour6 seulement de six atomes d'oxyg6ne, provenant par moiti6 des octa6dres TeO 6 et des t&ra6dres PO 4.Le Tableau (Nb,Ta)3As of M--M = 3.12 and 3.13 /k, M-As = 2.74 and 2.74 /k and As-As = 3.87 and 3.92 /k respectively. TaaAs is an ordered variant of NbaAs.

Phase equilibria and chemical vapor transport in the system Mo–Ta–As

“…The metalrich phases Ta 2 As and Ta 5 As 4 were prepared for the first time by Rundqvist et al [15] and the most Ta-rich phase, Ta 3 As, by Ganglberger et al [16]. Wang et al [17] obtained single crystals of Ta 3 As by CVT in tantalum crucibles and were thus able to characterize the new Ta 3 As structure type. Structural information on binary Ta-As phases is compiled in Table 1.…”

Tantalum-Niobium Mixing in Ta3-xNbxTeI7 (0 ≤ x ≤ 3)

“…The simple substitution of Nb or Ta into a structure where at least one corresponding (isostructural) pure binary compound is known. Examples of this category are legion, including Nb x Ta 1±x Te 4 [1], Nb x Ta 2±x Te 3 (Ta 2 Te 3 type) [2], Ta 6.18 Nb 14.92 S 8 (Nb 21 S 8 type) [9], Ta 1.79 Nb 0.21 S (Ta 2 S type) [9], Ta 1.376 Nb 1.126 As 0.897 (Ti 3 P type, with Nb 3 As and Ta 3 As) [10], and Cu 3 NbTaO 8 (= Cu 3 Ta 2 O 8 and Cu 3 Nb 2 O 8 ) [11].…”