Structural and superconducting properties of the system La<SUB>1&#8722;x</SUB>PrSr<SUB>x</SUB>CuO<SUB>4</SUB>

Structural and superconducting properties of La<SUB>1&#8722;x</SUB>PrSr<SUB>x</SUB>CuO<SUB>4</SUB> have been investigated. Substitution of Sr for La in LaPrCuO<SUB>4</SUB> (T'-structure), induces a transformation to the T-structure unlike in LaSmCuO<SUB>4</SUB> and LaGdCuO<SUB>4</SUB> where a transformation takes place from the T'- to the T<SUP>&#8727;</SUP>-structure. The transformation gets completed at x=0.2. These studies suggest that the rare earth ionic size is critical in the T' &#8594; T(T<SUP>&#8727;</SUP>) transition. Superconductivity is observed in samples with 0.1 &#8804;&#967;&#8804;0.25