Synthesis and structure of the subnitrides Ba2GeGaN and (BaxSr1-x)(3)Ge2N2; x approximate to 0.7

Journal article

We report the structure of the new subnitride Ba2GeGaN synthesized as crystals from the elements in a sealed Nb tube at 760 °C using a Na/Ba melt as the growth medium. Shiny black prisms of Ba2GeGaN crystallize in P21/m (No.11) with a=7.249(1) Å, b=4.210(1) Å, c=9.314(1) Å, β=108.87(1)° and Z=2. It contains infinite zigzag chains, 1 ∞[GeGaN4-], composed of alternating Ge2- and GaN2- units joined by Ge-Ga bonds. The structure is related to that of BaGe with alternate Ge atoms replaced by the isoelectronic GaN2- fragment. Such GaN2- fragments occur in CaGaN. We also report the occurrence of a solid solution between the previously reported subnitrides Ba3Ge2N2 and Sr3Ge2N2 which contain infinite chains, 1 ∞[Ge2-], and GeN4- 2 units. We have characterized one member of this solid solution with composition (Ba0.79(1)Sr0.21(1))3Ge2N 2 and crystallizing in P21/m (No. 11) with a=9.5109(9) Å, 6=4.0201(3) Å, c=10.0412(9) Å, β=113.06(1)° and Z=2. © 1997 Elsevier Science S.A.

Authors: Clarke, S; DiSalvo, F

• Publication status: Published
• Journal: JOURNAL OF ALLOYS AND COMPOUNDS
• Volume: 259
• Issue: 1-2
• Pages: 158-162
• Publication date: 1997-08-22
• DOI: 10.1016/S0925-8388(97)00095-9
• ISSN: 0925-8388
• Keywords: sodium flux; subnitride; ternary nitride