Effect of laser irradiation on activation energy, irreversibility field and upper critical magnetic field of bulk MgB2 superconductor
Küçük Resim Yok
Tarih
2016
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Springer New York LLC
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In this study, the role of laser irradiation on the upper critical field (Hc2), the irreversibility field (Hirr) and the activation energy (U0) of bulk MgB2 superconductor was first time investigated with the aid of magnetoresistivity measurements conducted at different applied magnetic fields in a range of 0–15 kOe as a function of temperature from 25 to 40 K. For this aim, a disk shaped MgB2 superconductor was produced and cut into two pieces. One of the pieces was irradiated under high vacuum conditions by using an Nd:YVO4 laser. The obtained results showed an increase in the critical temperature (Tc) by about 1 K after irradiation. Also, the values of Hc2(0) were respectively found to be around 143 and 151 kOe while the values of Hirr(0) were about 122 and 130 kOe for the reference and the irradiated samples. Using the thermally activated flux flow model the dependence of U0 on magnetic field was determined. The maximum U0 values of 0.43 and 0.83 eV in zero magnetic field were respectively obtained for the reference and the irradiated samples. Also, the magnetic field dependence of the critical current density Jc(B) values at different temperatures were slightly increased after the irradiation. These results point out that the superconducting properties of bulk MgB2 can be improved via laser irradiation. © 2016, Springer Science+Business Media New York.
Açıklama
Anahtar Kelimeler
Chemical activation, Irradiation, Magnetic fields, Magnetism, Superconducting materials, Applied magnetic fields, Critical temperatures, High-vacuum conditions, Irreversibility fields, Magnetic field dependences, Superconducting properties, Upper critical fields, Upper critical magnetic fields, Activation energy, Chemical activation, Irradiation, Magnetic fields, Magnetism, Superconducting materials, Applied magnetic fields, Critical temperatures, High-vacuum conditions, Irreversibility fields, Magnetic field dependences, Superconducting properties, Upper critical fields, Upper critical magnetic fields, Activation energy
Kaynak
Journal of Materials Science: Materials in Electronics
WoS Q Değeri
Q2
Scopus Q Değeri
Q2
Cilt
27
Sayı
6
