Thermoelectric Properties of YMn4+xAl8-x, -2 ≤ x ≤ 2.5

Artikel i vetenskaplig tidskrift, 2009

Seven samples within the series YMn 4+x Al 8 - x (-2.0 ≤ x ≤ 2.5) were synthesized using direct reaction of the elements. The thermoelectric properties of the samples were characterized by measurements of resistivity, thermal conductivity and thermopower. According to transport measurements, slight Mn-deficiency influences the electronic conductivity of the YMn 4+x Al 8 - x system, implying that the electronic structure is marginal to the metal-semiconductor boundary. Furthermore, the ZT values of the samples prepared in this study were low. Experimental results indicated that structurally ordered YMn 4 Al 8 shows metallic conductivity, whereas off-stoichiometric compounds displayed semiconductor-like behavior, at low temperatures. © 2008 Elsevier B.V. All rights reserved.