Effects of electron irradiation on superconducting properties of Bi2Sr2CaCu2O8/MgO superconductor composite
Abstract
Abstract
Among the challenges for superconducting devices to be applied in industry are the need for high transport critical current density (Jc) and sustainability of the device in different environment. For superconducting material to maintain high Jc, effective flux pinning centers are needed. The addition of small size MgO particles in bulk Bi2Sr2CaCu2O8 (Bi-2212) superconductor has been proven to enhance the effective flux pinning centers in the superconducting material. Nevertheless, the flux pinning properties of the superconducting materials may change if they are exposed to radioactive environment. Electron irradiation is one of the common techniques that can be used to study the impact of irradiation on superconducting materials. In this work, a small amount of nanosize MgO particles were used as the flux pinning centers for Bi-2212 superconducting material. The Bi-2212/MgO composite was heat treated and followed by partial melting and slow cooling. Some of the samples were subjected to electron irradiation using the facility at the Malaysian Nuclear Agency. Characterizations of non-irradiated and irradiated samples were performed via X-ray Diffraction Patterns (XRD), Scanning Electron Microscopy (SEM) and measurements of Jc dependence on temperature in self-field. Higher Jc indicates better flux pinning properties in irradiated superconductor composite. This is achieved if defects with larger radius with dimension comparable to the coherence length of the superconducting material were created. On the other hand, decreased in Jc indicates ineffective flux pinning and this is attributed to the overlapping of defects that break the superconducting region. Our study showed that electron irradiation deteriorated the flux pinning properties of the Bi-2212/MgO superconductor composite.
Abstrak
Antara cabaran-cabaran itu kerana alat-alat keberaliran lampau untuk digunakan dalam industri ialah perlukan ketumpatan arus gentingpengangkutan yang tinggi (Jc) dan ketahanan peranti dalampersekitaran lain. Kerana bahan mengalir lampau mengekalkan Jctinggi, fluks berkesan meletakkan pusat-pusat diperlukan. Tambahansaiz kecil zarah-zarah MgO dalam pukal Bi2Sr2CaCu2O8 (Bi- 2212)superkonduktor telah terbukti untuk meningkatkan fluks berkesanmeletakkan pusat-pusat dalam bahan mengalir lampau. Walaubagaimanapun , fluks meletakkan ciri-ciri bahan-bahan keberaliran lampau boleh berubah jika mereka ialah didedahkan kepada persekitaran radioaktif. Penyinaran elektron ialah satu daripadateknik-teknik umum yang boleh digunakan bagi mengkaji kesan penyinaran di bahan-bahan keberaliran lampau. Dalam tugas ini, sedikit zarah-zarah saiz-nano MgO telah digunakan apabila fluksmeletakkan pusat-pusat kerana bahan mengalir lampau Bi- 2212. Dwi 2212 / rencam MgO ada haba merawat dan diikuti oleh separapeleburan dan penyejukan yang perlahan. Beberapa contoh-contohbawah penyinaran elektron menggunakan kemudahan itu di Malaysian Nuclear Agency. Gambaran sifat tidak menerangi danmenerangi contoh-contoh telah diusahakan melalui X-ray Diffraction Patterns (XRD), Scanning Electron Microscopy (SEM) dan ukuran-ukuran pergantungan Jc di suhu di diri bidang. Jc lebih tinggimenunjukkan fluks lebih baik meletakkan ciri-ciri dalam menerangirencam superkonduktor. Ini mencapai jika kecacatan-kecacatandengan jejari lebih besar berdimensi setanding bagi panjang kekoherenan bahan mengalir lampau diwujudkan. Sebaliknya, mengurangkan dalam Jc menunjukkan fluks tidak berkesan meletakkan dan ini ialah dianggap berpunca daripada bertindihberpaling tadah itu memecahkan rantau keberaliran lampau. Kajian menunjukkan kami penyinaran elektron itu rosak fluks meletakkanciri-ciri Bi- 2212 / rencam superkonduktor MgO.
