AC-susceptibility measurements of Cu1−xTlxBa2Ca3Cu4O12−δ superconductor thin films with different thallium content

✍ Scribed by Nawazish A. Khan; M. Mumtaz; A.A. Khurram; P. Kameli

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 448 KB
• Volume: 468
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2007.12.005

✦ Synopsis

We have studied the superconductivity of Cu 1Àx Tl x Ba 2 Ca 3 Cu 4 O 12Àd (x = 0.8 and 0.5) thin films by AC-susceptibility measurements under various external AC magnetic field strengths. It is observed from these measurements that the v 00 peak of AC-susceptibility measurements which is associated with AC losses in the superconductor samples representing intergranular coupling and pinning strength of the samples is shifted to lower temperature after the application of external magnetic fields. It is observed from these measurements that in the samples with x = 0.5 the v 00 peak is shifted to lower temperature by applying very small AC field (i.e. H ac up to 50 A/m) whereas, the v 00 peak of thallium rich (x = 0.8) samples is only affected by higher magnetic fields up to 800 A/m. These results have shown that Cu 1Àx Tl x Ba 2 Ca 3 Cu 4 O 12Àd superconductor thin films with higher thallium content have enhanced granular connectivity and stronger flux pinning as compared to the samples with smaller thallium content.