Decrease of bulk pinning strength in deoxygenated YBCO single crystals
We measured the first and third harmonics of the complex ac susceptibility in YBCO single crystals with different oxygen contents (6.5 ≤ × ≤ 7). The amplitude of the ac field was varied in presence of an external dc field both applied parallel to the c-axis of the crystals. We give evidence that deo...
| Autores principales: | , |
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| Formato: | JOUR |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_03701972_v220_n1_p597_Moreno |
| Aporte de: |
| Sumario: | We measured the first and third harmonics of the complex ac susceptibility in YBCO single crystals with different oxygen contents (6.5 ≤ × ≤ 7). The amplitude of the ac field was varied in presence of an external dc field both applied parallel to the c-axis of the crystals. We give evidence that deoxygenation leads to a reduction of the bulk pinning strength and consequently to a stronger contribution of geometrical barriers. These results support the recently reported investigations showing that deoxygenation makes the YBCO crystals more anisotropic reducing the effective bulk pinning for quasi-two-dimensional vortices. We also show measurements for the same crystals with the ac field applied perpendicular to the c-axis. |
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