Structural and Thermoelectric Properties of Chimney–Ladder Compounds in the Ru-Mn-Si System
We have investigated phase relationships of the sesquisilicide alloys in the Ru-Mn-Si system. A series of chimney–ladder phases Ru1−xMnxSiy (0.14 ≤ x ≤ 0.97, 1.584 ≤ y ≤ 1.741) are formed over a wide compositional range between Ru2Si3 and Mn4Si7. We also investigated thermoelectric properties of the directionally solidified Ru1−xMnxSiy alloys as a function of Mn content and temperature. The dimensionless figure of merit ZT for alloys with high Mn content (x ≥ 0.75) increases as the Mn content increases. The alloy with x = 0.90 exhibits ZT as high as 0.76 at 874 K.