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The Effect of Using Different Y2O3 Layers on the Activation Energy and Irreversibility Line of MPMG YBCO Bulk at 1050 °C Growth Temperature       
Yazarlar
Öğr. Gör. Dr. Sedat KURNAZ Öğr. Gör. Dr. Sedat KURNAZ
Kastamonu Üniversitesi, Türkiye
Bakiye Çakır
Artvin Çoruh Üniversitesi, Türkiye
Alev Aydıner
Karadeniz Teknik Üniversitesi, Türkiye
Özet
In this study, three kinds of YBCO samples which are named Y1, Y2 and Y3 were fabricated by a melt–powder–melt–growth (MPMG) method. The Y1 sample was placed into a platinum (Pt) crucible without Y2O3, the Y2 sample was located on a Al2O3 crucible with a freely poured Y2O3 powder and the Y3 sample was located on a Al2O3 crucible with a 1-mm-thick buffer layer of Y2O3. YBCO samples were investigated by magnetoresistivity (ρ–T) measurements in dc magnetic fields (parallel to the c-axis) up to 5 T. The effect of the Y2O3 layer on the activation energy and irreversible flux of the samples was studied. The activation energies (U) were determined using the Arrhenius activation energy law from ρ–T. The power law relationship for U with H−α was investigated. α was calculated to find out which defects were dominant in the samples. Irreversibility fields (Hirr) and upper critical fields (Hc2) were obtained using 10 and 90% criteria of the normal-state resistivity value from ρ–T curves. Irreversibility lines (ILs) were estimated from the equation Hirr ∼ (1 − Tirr(H)/Tirr(0))n. The fitting results to giant flux creep and vortex glass models were discussed.
Anahtar Kelimeler
Activation energy | Giant flux creep | Irreversibility field | MPMG method | Pinning mechanism | Vortex glass | Vortex liquid | Y O layer 2 3
Makale Türü Özgün Makale
Makale Alt Türü SSCI, AHCI, SCI, SCI-Exp dergilerinde yayımlanan tam makale
Dergi Adı JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM
Dergi ISSN 1557-1939
Dergi Tarandığı Indeksler SCI-Expanded
Dergi Grubu Q4
Makale Dili İngilizce
Basım Tarihi 10-2018
Cilt No 31
Sayı 10
Sayfalar 3167 / 3174
Doi Numarası 10.1007/s10948-017-4551-1
Makale Linki http://dx.doi.org/10.1007/s10948-017-4551-1