Measurements of ultra-low DC fields by high-T c superconducting cores: The effect of calcination temperature

Topal U., Alikma F., Birlikseven C., UZUN O., KÖLEMEN U.

Journal of Alloys and Compounds, cilt.530, ss.91-96, 2012 (SCI-Expanded, Scopus) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 530
  • Basım Tarihi: 2012
  • Doi Numarası: 10.1016/j.jallcom.2012.03.085
  • Dergi Adı: Journal of Alloys and Compounds
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.91-96
  • Anahtar Kelimeler: 2nd harmonic signal, DC-magnetometer, High-T c superconductor, Magnetic field sensor, Ultra-low DC field measurements
  • Samsun Üniversitesi Adresli: Hayır

Özet

In this study, the effects of weak links between grains of the ceramic superconductors on the sensitivity of a DC magnetic field sensor were examined. The evolution of 2nd harmonic signal strength, which determines the magnetometer sensitivity, with critical current density J c was especially analyzed. The J c values were adjusted by synthesis of Y-123 superconductors at different calcination temperatures. It was observed that the strength of 2f signal increases as the calcination temperature and so, the J c values increases. This is contrary to the common expectations. Our experiments have shown that the 2f signal changes quite linearly with DC field in a wide dynamic range (10 -4 to 10 -9 T) on the sample calcined at 950 °C. The ways of measuring DC fields as low as 1 nT are described in the paper. © 2012 Elsevier B.V. All rights reserved.