Ag2Te is a promising thermoelectric compound, and Ni is commonly used as a barrier layer. The interfacial reactions in the Ni/Te and Ni/Ag2Te couples are examined at 200 degrees C and 250 degrees C. To illustrate the reaction paths in the Ni/Ag2Te couples, the Ag-Ni-Te isothermal sections at 200 degrees C and 250 degrees C are determined based on experimental results of this study and related phase equilibria information. There is no ternary compound phase found and the phase relationships are same at 200 degrees C and 250 degrees C. The reaction paths of the two reaction couples are identical at these two temperatures. Three intermediate phases, Ni3Te2, NiTe0.775 and NiTe2, are formed in the Ni/Te couples. The reaction rate increases significantly at 250 degrees C, and is about six times higher than that at 200 degrees C. Only the Ni3Te2 and Ag phases are observed in the Ni/Ag2Te couples. The reaction path is Ag2Te/Ni3Te2/Ag/Ni in the Ni/Ag2Te couples at both 200 degrees C and 250 degrees C. (C) 2016 Elsevier B.V. All rights reserved.