  Thermochemical characteristics of Nd1+xBa2-xCu3Oy solid solutions were
studied by solution calorimetry. Dependences of formation enthalpies from Nd
content were constructed. It was established that decomposition of solid
solution on the basis of Nd123 phase took place both in inert and in oxygen
atmosphere. As a result of decomposition the different mixtures such as solid
solutions with increasing and decreasing Nd content and BaCuO2 were formed.
Obtained thermochemical data were compared with results of measurements of
transport characteristics. It was established that treatment of samples at
550-600 C led to increasing critical current and decreasing Tc.
