화학공학소재연구정보센터
Journal of the American Chemical Society, Vol.138, No.33, 10636-10644, 2016
Metal Nitrides Grown from Ca/Li Flux: Ca6Te3N2 and New Nitridoferrate(I) Ca-6(LixFe1-x)Te2N3
Two new tellurium-containing nitrides were grown from reactions in molten calcium and lithium. The compound Ca6Te3N2 crystallizes in space group R (3) over barc (a = 12.000(3)angstrom, c = 13.147(4)angstrom; Z = 6); its structure is an anti-type of rinneite (K3NaFeCl6) and 2H perovskite related oxides such as Sr3Co2O6. The compound Ca-6(LixFe1-x)Te2N3 where x approximate to 0.48 forms in space group P4(2)/m (a = 8.718(3)angstrom, c = 6.719(2)angstrom; Z = 2) with a new stuffed anti-type variant of the Tl3BiCl6 structure. Band structure calculations and easily observable red/green dichroic behavior indicate that Ca6Te3N2 is a highly anisotropic direct band gap semiconductor (E-g = 2.5 eV). Ca-6(LixFe1-x)Te2N3 features isolated linear N-Fe-N units with iron in the rare Fe1+ state. The magnetic behavior of the iron site was characterized by magnetic susceptibility measurements, which indicate a very high magnetic moment (5.16 mu(B)) likely due to a high degree of spin-orbit coupling. Inherent disorder at the Fe/Li mixed site frustrates long-range communication between magnetic centers.