Combined Experimental and Density Functional Theory Studies on the Crystal Structures and Magnetic Properties of Mg(Mg1-xMnx)(2)Sb-2 (x approximate to 0.25) and BaMn2Sb2

Reported are the synthesis and structural characterization of two ternary transition metal intermetallic compounds, Mg(Mg1-xMnx)(2)Sb-2 (where x is approximately 0.25) and BaMn2Sb2 center dot Mg(Mg2.50(3)Mn0.5)(2)Sb-2 crystallizes in the trigonal space group P (3) over bar m1 (no. 164) and belongs to the CaAl2Si2-type, while BaMn2Sb2 is isostructural with the body-centred tetragonal ThCr2Si2-type (14/mmm, no. 139). Both structures have been refined from single-crystal X-ray diffraction data and their magnetic properties determined with the aid of a SQUID-magnetometry. The experimental results have been corroborated by electronic-structure calculations using the linear muffin-tin orbital (LMTO) method. Spin-polarized density-functional theory calculations confirm the antiferro-magntically ordered magnetic structures. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)