Effect of rare earth ion substitution on the magnetic and transport properties of Pr \(_{\mathsf{0.7}}\)RE \(_\mathsf{0.04}\)Sr \(_\mathsf{0.26}\)MnO\(_\mathsf{3}\) (RE = Er\(^\mathsf{3 + }\), Tb\(^\mathsf{3 + }\) and Ho\(^\mathsf{3 + }\))

The effect of rare earth ion (RE = Er3 + , Tb3 + , Ho3 + ) substitution in Pr0.74Sr0.26MnO3 (PSMO(0.26)) on the magnetic and transport properties is reported. It is found that even for a small concentration of substitution of Pr3 + ions by Er3 + , Tb3 + , or Ho3 + ions there is a significant change in the transport and magnetic properties compared to the parent compound Pr0.74Sr0.26MnO3. The observed changes are attributed to the increase in the average A-site disorder upon substituting smaller ions (ionic radius of Er3 + = 1.062 A, Ho3 + = 1.072 A, Tb3 + = 1.095 A) in place of bigger Pr3 + ion (ionic radius = 1.179 A). The Ho3 + substituted sample was found to behave anomalously when compared to the other two rare earth ion-substituted (Tb3 + and Er3 + ) samples. Such anomalous behaviour could most likely be caused by the magnetic coupling of the Ho and Mn ions.