Systems Based on InN
The Sr 6 In 4 (In 0.32 Li 0.92 )N 2.49 quaternary compound, which crystallizes in the cubic structure with the lattice parameter a = 1437.52 ± 0.04 at 173 ± 2 K, is formed in the In–Li–Sr–N system (Bailey et al. 2005). To obtain the title compound, two initial reactions were performed. In both cases, Na (200 mg), Sr (88 mg), In (70 mg), NaN3 (70 mg) (molar ratios of Na/Sr/In/N2 = 16.0:1.6:1:2.6), and Li (3.5 mg) were loaded into a Nb tube. The Nb containers were sealed under 0.1 MPa of Ar in an arc furnace and then were themselves sealed under vacuum in fused silica tubes. These starting materials were heated to 800°C in 15 h; they remained at that temperature for 24 h and then were linearly cooled to 200°C over 200 h, at which point the furnace was shut off and allowed to cool naturally. Upon completion of the reactions, unreacted sodium was removed by sublimation from the products by heating the Nb tubes to 350°C under a pressure of approximately 0.1 Pa for 8 h.