Mg 2 Si 0.45 Sn 0.55 Based Thermoelectric Solid Solutions with Band Convergence

Mg2(1+x)Si0.45Sn0.537Sb0.013 (x = 0.04, 0.06, 0.08, 0.10, 0.12) compounds were synthesized by a B2O3 flux method.22 Elemental Mg (99%), Si (99.9%), Sn (99.5%) and Sb (99.999%) powders were utilized. All preparation steps were performed in an argon glove box. Raw powders were weighed, and thoroughly mixed in an agate mortar. The starting materials were transferred into an alumina crucible, covered by B2O3 powders and then compacted. The crucibles were placed into a chamber furnace, heated at 973 K for 10 h and finally cooled down to room temperature. The ingots were ground and sieved to ~50 μm and hot pressed in a graphite die of Φ 12.7 mm under a pressure of 80 MPa at 1025 K for 2 h, resulting in compact pellets for property analysis.
Mg2(1+x)Si0.45Sn0.537Sb0.013
x
0.04
Mg2(1+x)Si0.45Sn0.537Sb0.013
x
0.06
Mg2(1+x)Si0.45Sn0.537Sb0.013
x
0.08
Mg2(1+x)Si0.45Sn0.537Sb0.013
x
0.10
Mg2(1+x)Si0.45Sn0.537Sb0.013
x
0.12
Elemental Mg
99%
%
Si
99.9%
%
Sn
99.5%
%
Sb
99.999%
%
crucibles
heated
973 K
K
crucibles
heated
10 h
h
ingots
ground and sieved
50 μm
μm
graphite die
hot pressed
12.7 mm
mm
ingots were ground and sieved
pressure
80 MPa
MPa
ingots were ground and sieved
hot pressed
1025 K
K
ingots were ground and sieved
hot pressed
2 h
h