Reactive molten-flux assisted syntheses of single crystals of Cs₁₉Ln₁₉Mn₁₀Te₄₈ (Ln = Pr and Gd) crystallizing in a new structure type

Abstract

Two new complex layered quaternary tellurides, Cs19Ln19Mn10Te48 (Ln = Pr and Gd), were synthesized by the reactive molten flux method. The title compounds represent an unprecedented structure type.

Five coordinated Mn in Ba4Mn2Si2Te9: synthesis, crystal structure, physical properties, and electronic structure

“…of four (0.66 Å). The Mn–Te distances in Mn(2)Te 4 units (2.7207(14)–2.7749(15) Å) are in good agreement with Mn 2+ –Te distances of BaLn 1− x Mn 2 Te 5 (Ln = lanthanides; 2.697(2) Å–2.744(2) Å), 43 Cs 19 Ln 19 Mn 10 Te 48 (2.683(3) Å–2.7913(3) Å), 44 and Ba 2 MnTe 3 (2.640(1)–2.733(1) Å). 11…”

“…Dalton Transactions slightly longer than the Mn-Te distances of Mn( 2 44 and Ba 2 MnTe 3 (2.640(1)-2.733(1) Å). 11 The structural motifs/building blocks of the Ba 4 Mn 2 Si 2 Te 9 structure can be described based on the coordination polyhedra of Si and Mn atoms.…”

ABa6Cu31Te22 (A = K, Rb, Cs) Featuring Polyanionic Copper–Telluride Frameworks with Ultralow Thermal Conductivity

“…After SCXRD and EDS determined the composition of new phases as A Ba 6 Cu 31 Te 22 , the synthesis was performed from stoichiometric Ba:Cu:Te ratios excluding Si, as described in the Experimental Section. Synthesis of multinary phases in salt fluxes is a common practice, a notable recent example being Cs 19 Ln 19 Mn 10 Te 48 ( Ln = Pr, Gd) . The formation of tellurium-containing binary and ternary impurities has been reported for synthesis of other multinary tellurides, such as Ba 3 ScTe 5 , Ba 2 GdMn 2 Te 5 , and Ba 4 Mn 2 Si 2 Te 9 . ,, The experimental and calculated PXRD patterns and the general polyhedral view of the unit cell of A Ba 6 Cu 36−δ Te 22 are provided in Figure .…”

“…Examples of direct bandgap tellurides were also reported, such as TlInTe 2 . Most of the reported materials exhibit VBM dominated by Te states and CBM dominated by transition metal states, such as in the case of Cs 19 RE 19 Mn 10 Te 48 ( RE = Gd, Pr) …”

“…Synthesis of multinary phases in salt fluxes is a common practice, 10 a notable recent example being Cs 19 Ln 19 Mn 10 Te 48 (Ln = Pr, Gd). 44 The formation of tellurium-containing binary and ternary impurities has been reported for synthesis of other multinary tellurides, such as The crystal structure can be separated into two motifs: (i) the motif with [BaTe 8 ] and [ATe 12 ] polyhedral units (Figure 2) and (ii) the motif consisting of the tetrahedral [CuTe 4 ] and trigonal pyramidal [CuTe 3 ] units (Figure 3). The distorted square antiprism [BaTe 8 ] (red in Figure 2a) has a volume of ∼76 Å 3 , with Ba−Te distances in the range of 3.43−3.61 Å across all three compositions (Table SI8).…”