Measurements of chi' and chi `' have been performed on directionally solidified YBCO 211 doped samples. We analyze the variations of structural and superconducting properties as a function of a relevant fabrication parameter such as the pulling rate within a region with fixed thermal gradient. Measurements are made at different AC magnetic field and frequencies. The effects of intra- and inter-domain screening currents are compared among samples with different superconducting properties. Although the XRD shows quasi-single crystal behaviour, residual granular-like effects are observed. However, in good quality samples the dissipation due to the inter-domains coupling is orders of magnitude lower than the dissipation in sintered specimens.
AC susceptibility measurements on directionally solidified YBCO samples
Vecchione;
1996
Abstract
Measurements of chi' and chi `' have been performed on directionally solidified YBCO 211 doped samples. We analyze the variations of structural and superconducting properties as a function of a relevant fabrication parameter such as the pulling rate within a region with fixed thermal gradient. Measurements are made at different AC magnetic field and frequencies. The effects of intra- and inter-domain screening currents are compared among samples with different superconducting properties. Although the XRD shows quasi-single crystal behaviour, residual granular-like effects are observed. However, in good quality samples the dissipation due to the inter-domains coupling is orders of magnitude lower than the dissipation in sintered specimens.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
