Clathrates are thermoelectric materials that are used in waste heat recovery applications. This study tested the thermophysical properties of the n-doped clathrate Ba8Ga16Ge30 after gallium (Ga) and germanium (Ge) substituted antimony (Sb) and zinc (Zn). A TPS instrument measured the thermal conductivity of n-Ba8Ga16Ge30 with the transient plane source (TPS) method. Results showed that for almost every sample, thermal conductivity decreased inversely to temperature, then increased ...