Combined Experimental and Density Functional Theory Studies on the Crystal Structures and Magnetic Properties of Mg(Mg_1–xMn_x)₂Sb₂ (x ≈ 0.25) and BaMn₂Sb₂

Abstract

Reported are the synthesis and structural characterization of two ternary transition metal intermetallic compounds, Mg(Mg1–xMnx)2Sb2 (where x is approximately 0.25) and BaMn2Sb2·Mg(Mg2.50(3)Mn0.5)2Sb2 crystallizes in the trigonal space group P$\bar {3}$m1 (no. 164) and belongs to the CaAl2Si2‐type, while BaMn2Sb2 is isostructural with the body‐centred tetragonal ThCr2Si2‐type (I4/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 antiferromagntically ordered magnetic structures. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

Angle-resolved photoemission observation of Mn-pnictide hybridization and negligible band structure renormalization in BaMn2As2 and BaMn2Sb2Zhang1, Richard2, Roekeghem3 et al. 2016Phys. Rev. B234270View full textAdd to dashboardCite

“…The 2D-curvature is an improved version of the laplacian to track dispersive features in image plots, which is based on the Gauss theory of curvature. We observe two hole bands at the BZ center, none of them crossing E F , as expected from the antiferromagnetic ground state and semiconducting behavior of BaMn 2 As 2 [9,14,15]. While the inner hole band is gapped by about 200 meV below E F for both k z values, the band gap of the outer one varies from nearly 93 to 300 meV between Γ and Z.…”

Electronic structure and magnetism inBaMn2As2andBaMn2An1, Sefat2, Singh3 et al. 2009Phys. Rev. B137221451View full textAdd to dashboardCite

“…17 We find that the Mn compounds are rather different from the Fe, Co and Ni compounds in that there is much stronger hybridization with the pnictogen p states. This leads to an electronic structure that cannot be regarded as derived from that of the Fe compound with a different electron count.…”

“…2, 17 We note that BaMn 2 Sb 2 , BaMn 2 As 2 and BaFe 2 As 2 are composed of common, inexpensive elements, which as mentioned is an important consideration for some thermoelectric ap-plications. Key questions concern the relationship between BaMn 2 As 2 and BaMn 2 Sb 2 , and that between the Mn and Fe compounds, as well as the related issue of whether the conductivity in the Mn compounds can be improved by doping, while at the same time maintaining high thermopowers.…”

“…On the other hand, the Mn compounds, BaMn 2 P 2 , BaMn 2 As 2 and BaMn 2 Sb 2 are known phases as are the corresponding Ca, Sr and Eu materials, though with structural distortions in some cases. 13,14,15,16,17 From a practical point of view, there are several reports of remarkably high thermopowers accompanied by metallic conduction in the Fe based superconducting phases. 18,19,20,21,22 These materials have relatively narrow manifolds of Fe d bands near the Fermi energy.…”

Antiferromagnetism in semiconductingSrMn2Sb2andBaMn2Sb2single crystals

“…Previous theoretical electronic structure studies on BaMn 2 Sb 2 suggested a G-type AFM ordering [61,62], but T N and the AFM structure have not been experimentally determined. Transport measurements revealed that BaMn 2 Sb 2 has a room-temperature Seebeck coefficient of ∼225 μV/K, consistent with semiconducting behavior.…”