Structure and electrical conductivity of the perovskites Pr$_{1-x}$Sr$_{x}$MnO$_{3}$ ($x$ = 0; 0.15; 0.25)

Pr$_{1-x}$Sr$_{x}$MnO$_{3}$ manganites ($x$ = 0; 0.15; 0.25) were synthesized by the solid-phase method at a temperature of 1250$^{\circ}$C and have an orthorhombic perovskite-like structure (space group $Pbnm$). A comprehensive study of the effect of praseodymium substitution with strontium on the temperature features of the transformation of the crystal structure of the studied perovskites was performed using high-temperature radiography and differential thermal analysis. It was determined that the temperature of the Jahn-Тeller effect significantly decreases with the introduction of strontium. It is established that all samples have a semiconductor character of conductivity. Strontium doping significantly increases the electrical conductivity of praseodymium manganites, especially at temperatures below 450$^{\circ}$C.