| Popis: |
Vanadium (V) doped for Cu-site in YBa 2 Cu 3 O 7−δ samples prepared by ceramic technique have been characterised by a.c. susceptibility technique and d.c. magnetisation measurements. Detailed magnetisation measurements on randomly oriented powdered sample of YBa 2 (Cu 0.98 V 0.02)3 O 7−δ as a function of temperatures and field exhibit pronounced M(H) hysteresis loops indicative of large flux pinning even as T approaches T c . It is believed that, the flux pinning arises due to the preferential substitution of V on Cu(2)-site, which acts as a pinning centre. The critical current density, J c , deduced from the M(H) data at 10K, varies from 4 KOe to 12 KOe respectively, which is nearly seven times larger than the J c of the pristine 1-2-3 powdered sample. The behaviour of J c in the magnetic fields is explained in terms of the flux creep model. |
