Study of the thermodynamic properties of the metallic compounds Sr(NH3)6 and Li(NH3)4

The metallic compounds Sr(NH3)6 and Li(NH3)4 are prepared in vacuum within cells of quartz.The non-reproducibility of Jacobs’ measurements of the heat capacity at high temperature of the compound Sr(NH3)6 led us to reconsider the thermal studies. Our measurements by differential thermal analysis (D.T.A.) were obtained by the analysis of the phase shift between the piloting and the differential signals.The metallic compound Li(NH3)4 was also examined by the mean of D.T.A. A detailed study has been carried out in a range of temperature 25–90 K, where the results obtained shows a second-order transition at 23 K, which can be compared with these observed in the case of deutered compound.