Effect of ${\hbox{Eu}}^{+3}$ on Flux Pinning Characteristics of Grain Aligned High-${T}_{c}$ Superconductor $\hbox{Sm}_{1-{\rm x}}\hbox{Eu}_{\rm x}\hbox{Ba}_{2}\hbox{Cu}_{3}\hbox{O}_{7-\delta}$

Flux pinning characteristics of grain aligned high-
Tc
superconductor Sm
_1-x
Eu
_x
Ba
₂
Cu
₃
O
_7-s
(where x=0.0, 0.3, 0.5, 0.7, 0.9) were studied by magnetization data. Samples were prepared by solid state reaction and aligned under high magnetic field of 6 T. Results show that the transition temperature
Tc
and critical current density
Jc
was found to enhanced in optimal doped samples (x = 0.5-0.7). Peak positions of pinning force density F
_p,max
were shifted towards higher fields in optimal doped samples. Furthermore, the normalized pinning force density showed peaks at lower reduced fields. Results are interpreted on the basis of presence of ionic radius difference between Sm
⁺³
and Eu
⁺³
and secondary phases which act effectively at high temperature and low fields.