A new type of thermoelectric material, EuZn2Sb2

Abstract

Polycrystalline EuZn(2)Sb(2) is prepared by direct reaction of the elements. Its composition, structure, magnetism, heat capacity, and thermoelectric properties have been investigated. EuZn(2)Sb(2) crystallizes in p3m space group with a=4.4932(7) A and c=7.6170(10) A. Antiferromagnetic ordering is detected at the Neel temperature of 13.06 K, and the saturation magnetization reaches 6.87mu(B)Eu at 2 K and 7 T. Eu ion has +2 valence. Its Hall effects are characterized by a high positive Hall coefficient of +0.226 cm(3)C, proper carrier concentration of 2.77x10(19)cm(3), and high carrier mobility of 257 cm(2)V s at 300 K. This compound shows high p-type Seebeck coefficient (+122 to +181 muVK), low lattice thermal conductivity (1.60-0.40 Wm K), and high electrical conductivity (1137-524 Scm). The obtained figure of merit and powder factor reach 0.92 and 20.72 muWcm K(2), respectively. The thermoelectric properties of EuZn(2)Sb(2) are encouraging.

Thermoelectric transport properties of CaMg2Bi2, EuMg2BiMay1, McGuire2, Singh3 et al. 2012Phys. Rev. B

“…In the analogous antimonides, high zT is obtained for Seebeck coefficients between approximately 180 and 250 µV/K. 1,3,5,7 In CaMg 2 Bi 2 , the calculation results qualitatively suggest optimal doping levels near 5×10…”

“…The highest figure of merit reported within this family of materials is zT = 1.2 at 700 K in YbCd 1.6 Zn 0.4 Sb 2 , 1 while zT values between 0.5 and 1.1 are typical. [2][3][4][5][6][7][8] In general, ternary antimonides that are understood using Zintl chemistry have received significant attention within the thermoelectric community due to their tunability and structural complexity. [9][10][11][12][13][14][15][16][17][18] However, the analogous bismuthides have received much less attention.…”

Higher thermoelectric performance of Zintl phases (Eu 0.5 Yb 0.5 ) 1−x Ca x Mg 2 Bi 2 by band engineering and strain fluctuation

“…8A). Such a ZT value is competitive with the reported Sb-based p-type Zintl phases (22,26,27,50) and even other good p-type skutterudites (51) and half-Heuslers (52) in this temperature range (Fig. 8B).…”

“…Remarkable achievements have been reported with maximal ZT around or more than 1, e.g., β-Zn 4 Sb 3 (20,21), Yb 14 Mn 1−x Al x Sb 11 (22,23), and A y Mo 3 Sb 7-x Te x (24). In particular, Zintl phases AB 2 Sb 2 (A = Ca, Yb, Eu, Sr; B = Zn, Mn, Cd, Mg) (25)(26)(27)(28)(29) crystallizing in CaAl 2 Si 2 structure have been extensively studied with the highest ZT for YbZn 0.4 Cd 1.6 Sb 2 ∼ 1.2 at 700 K. The A sites of these materials have been shown to contain exclusively divalent ions, which are limited to alkalineearth-based and rare-earth-based elements like Eu and Yb, whereas B is a d 0 , d 5 , d 10 transition metal or a main-group element like Mg 2+ (30,31). Despite the extensive research on Zintl antimonides, analogous Bi-based Zintl materials have received little attention, even given the competitive TE performance of this system.…”

Thermoelectric Properties of Polycrystalline SrZn2Sb2 Prepared by Spark Plasma Sintering

“…1). Promising ZT-values were found for the ternaries EuZn 2 Sb 2 with ZT = 0.92 at 713 K, 4 EuCd 2 Sb 2 with ZT = 0.6 at 617 K, 5 BaZn 2 Sb 2 with ZT = 0.31 at 675 K, 6 for compounds in the quaternary systems Ca x Yb 1Àx Zn 2 Sb 2 (x = 1) with ZT = 0.56 at 773 K, 7 Eu(Zn 1Àx Cd x ) 2 Sb 2 (x = 0.1) with ZT = 1.06 at 650 K, 8 YbCd 2Àx Zn x Sb 2 (x = 0.4) with ZT = 1.2 at 700 K, 9 and YbZn 2Àx Mn x Sb 2 (x = 0.1) with ZT = 0.65 at 726 K. 10 The good thermoelectric properties of these materials were attributed to the similar electronegativities of Zn, Cd, and Sb, leading to sufficient carrier mobility, as well as the high atomic mass of Sb, leading to low lattice thermal conductivity. 11 Another representative for this type of compounds is SrZn 2 Sb 2 ( Fig.…”