Differential scanning calorimetry (DSC) measurements of 37 polycrystalline LaH x (2 0<x <3 0) were performed in this work. Samples were synthesized by a direct reaction of a metal with hydrogen at temperat...Differential scanning calorimetry (DSC) measurements of 37 polycrystalline LaH x (2 0<x <3 0) were performed in this work. Samples were synthesized by a direct reaction of a metal with hydrogen at temperatures higher than 250 ℃ (depending on the final composition). DSC measurements were performed in the temperature range of 110～400 K. For the samples in the range of 2 13< x <2 40 single DSC peaks were detected. In the composition range x >2 45 much more complicated DSC signals (double, triple etc. peaks) were observed which some of them were up to 4 phase transformations. Based on these measurements and carried out on high purity samples and supported by high accuracy hydrogen content determination, a new T-x phase diagram for 110< T <400 K and 2< x <3(LaH x ) was proposed. This new phase diagram shows an up to now unknown complexity phase relationships with the existence of at least 11 of phases at T <400 K.展开更多
文摘Differential scanning calorimetry (DSC) measurements of 37 polycrystalline LaH x (2 0<x <3 0) were performed in this work. Samples were synthesized by a direct reaction of a metal with hydrogen at temperatures higher than 250 ℃ (depending on the final composition). DSC measurements were performed in the temperature range of 110～400 K. For the samples in the range of 2 13< x <2 40 single DSC peaks were detected. In the composition range x >2 45 much more complicated DSC signals (double, triple etc. peaks) were observed which some of them were up to 4 phase transformations. Based on these measurements and carried out on high purity samples and supported by high accuracy hydrogen content determination, a new T-x phase diagram for 110< T <400 K and 2< x <3(LaH x ) was proposed. This new phase diagram shows an up to now unknown complexity phase relationships with the existence of at least 11 of phases at T <400 K.
