  We studied thermochemical characteristics of the Sm1+xBa2-xCu3Oy single
crystals by solution calorimetry. Dependences of formation enthalpies from
samarium content were constructed. It was established that solid solutions on
the bases of Sm123 could be decomposed both in inert and in oxygen atmosphere
into different mixtures. We supposed that solid solutions decomposition could
lead to increasing critical current density. We assumed from thermochemical
data that Jc could be greater for samples prepared in oxygen than for samples
synthesized in inert atmosphere. We confirmed these assumptions by comparison
of obtained thermochemical data with transport properties measured in
literature. We also investigated temperature dependences of resistance in the
temperature range of 300-550 K during slow heating. As it was shown there was
anomaly of resistance near 500 K. The origin of this anomaly was discussed.
