Thermoelectric properties and microstructure of Mg3Sb2

Zintl phases for thermoelectric devices

“…The (Zn 2 Sb 2 ) 2− framework has good hole mobility due to its low polarity, in contrast to the polar covalent Mg 3 Sb 2 with similar structure which despite some promising reports, is a poor thermoelectric. 20 The bonding to the Ca site is ionic and CaZn 2 Sb 2 is a semiconductor with a band gap of about 0.25 eV. The less electropositive Yb cation makes YbZn 2 Sb 2 slightly electron deficient so that it is a heavily doped p-type semiconductor with metal-like transport properties.…”

Combined Experimental and Density Functional Theory Studies on the Crystal Structures and Magnetic Properties of Mg(Mg1–xMnx)2Sb2 (x ≈ 0.25) and BaMn2Sb2

“…[7][8][9][10][11][12][13][14][15] Of specific mention as well are the very recent reports identifying several AM 2 Sb 2 antimonides as prospective materials for thermoelectric energy conversion. [16][17][18][19] Our attention in these compounds, particularly in the AMn 2 X 2 pnictides (A = Ca, Sr, Ba, Eu and Yb) was drawn after the realization that their peculiar magnetic behaviour arises from complex magnetic interactions within very simple atomic arrangements, e.g. [Mn 2 X 2 ]…”

“…A survey of the literature showed that MgMn 2 Sb 2 is not known yet, [1] although α-Mg 3 Sb 2 with the CaAl 2 Si 2 -type and its Zn-substituted variant Mg(Mg 1-x Zn x ) 2 Sb 2 (x Ͻ 0.7) [19,22] are recognized to exist. This could be due to the fact that the melting point of the Mn is higher than the boiling point of Mg, [23] rendering the traditional high-temperature approach ineffective.…”

Role of Structures on Thermal Conductivity in Thermoelectric Materials

“…A ZT of 0.55 at 600K was initially attributed to the phase Mg 3 Sb 2 (space group P3m1) which was invalidated with a maximum of ZT of 0.2 at 875K [Condron 2006]. Moreover, the phase looses Mg and oxidizes above 900K.…”