The gallium-rich region of the Ce–Ag–Ga system

Crystal growth and properties of Ln2Ag1−xGa10−y (Ln=La, Ce), a disordered variant of the Ce2NiGa10-structure type

“…The presence of large atomic displacement parameters, anomalies in the electron difference maps, and anomalous residual electron density are indications of disorder at the M1, Ga2, Ga5, and Ga6 sites. Mixing between Ag and Ga has been reported previously in AgGa-containing intermetallic compounds due to the similar size, electronegativity, and coordination preferences of Ag and Ga [20][21][22][23][24][25][27][28][29][30][31]38]. The occupancy and atomic displacement parameters of M1 (Ag1+Ga1), Ga2, Ga5, and Ga6 sites were first refined separately and then together to yield the occupancies shown in Table 2.…”

“…This includes Ga-Ga contacts as well as Ga-T (T¼ transition metal) contacts in these phases. In previously reported YbGa 5 , a coordination of four can be obtained for all the Ga atoms by applying limits on interatomic distances found in previously published Ln:Ga (Ln ¼lanthanide) binary and Ln:Ag:Ga (Ln ¼lanthanide) ternary phases [20][21][22][23][24][25][26][27][28][29][30][31][32]. This approach results in the three most-likely components, shown in brackets 1-3 of Fig.…”

“…In the distorted bicapped Ga cubes of YbGa 5 , the authors suggested that the intrinsic disorder and split atom positions stem from the tendency of Ga to achieve the optimum coordination of four [41]. Previously published Ln:Ga (Ln ¼lanthanide) binary and Ln:Ag:Ga (Ln¼lanthanide) ternary phases depict Ga in a four coordinate environment (with interatomic contacts between 2.5 and 2.6Å) [20][21][22][23][24][25][26][27][28][29][30][31][32]. This includes Ga-Ga contacts as well as Ga-T (T¼ transition metal) contacts in these phases.…”

“…Although the structure of several Ln:Ag:Ga (Ln ¼lanthanide) intermetallic compounds such as Ln(Ag,Ga) 4 (Ln¼ La-Nd, Sm, Yb) [20,21], Ln 3 (Ag,Ga) 11 (Ln ¼Y, Gd-Yb) [22,23], LnAgGa 2 (Ln¼Gd, Yb, Y) [23][24][25], LnAgGa (Ln ¼Tb-Ho) [26], Ln(Ag,Ga) 2 (Ln ¼La-Nd, Sm-Lu, Y) [23,27,28], Ln 5 (Ag,Ga) 19 À x (Ln¼Gd, Tb; x $ 2.2) [29], CeAg 4.12 Ga 6.88 [30], CeAg 1.25 Ga 4.25 [30], Gd 14 (Ag,Ga) 51 [25], Gd(Ag,Ga) [25], and Ln(Ag,Ga) 3 (Ln ¼Sm, Gd, Tb-Tm, Lu) [31] have been reported, the structure determination of most are from polycrystalline samples and the physical properties of most of these compounds have not been investigated. Here we report the flux growth and characterization of Ln 2 Ag 1 À x Ga 10 À y (Ln ¼La, Ce), a disordered variant of the Ce 2 NiGa 10 structure-type [32].…”

The interactions between the components in the Gd–Ag–Ga system

“…At present the component interactions have been studied partially or completely only in three systems Ln-Ag-Ga (Ln = Y [1], Ce [2], Tb [3]). As it is known, Gd occupies a special place among the rare-earth metals, being situated on the border between the cerium-and yttrium-subgroups.…”