MODERN PHYSICS LETTERS B, vol.19, no.6, pp.331-340, 2005 (SCI-Expanded)
In the present work, the magnetic properties of high-T Bi1.7Pb0.3Sr2Ca2-xSmxCu3O12 system (x = 0.03) have been investigated, for different temperatures below T,. Substitution of Sm3+ for Ca2+ is found to change the superconducting properties of the system, despite the weak paramagnetic nature of the Sm3+ ion. The dc magnetization measurements performed on the compound reveal that the superconducting regions decrease with increasing temperature and magnetic field. The results are explained on the basis of a possible reduction of hole concentration with trivalent rare-eaxth ion substitution, and also on the basis of the magnetic nature of the substituted Sm3+ ions.