Fast Magnetic Measurement of the HTc Superconducting Materials

MHY-1

The measurements of magnetic characteristics of the high-Tc superconductors give a valuable information about basic parameters which characterize their superconducting state and information about the structure of penetrating magnetic flux and processes connected with their dynamics. A simple measuring method and measuring system for fast measurement of magnetic characteristics of HTc superconductors at 77K were designed. The measuring system consists of a coaxial second order low-Tc SQUID gradiometer with the spectral sensitivity 8x10^-12 T/m²Hz^1/2, electronic unit MHY-1 and two concentric oppositely oriented coplanar coils for generation of the magnetizing fields. This method does not require inserting the sample into the cryostat and moving it in the gradiometric antenna during magnetization and relaxation measurements. Such solution enables quick exchange of measured samples, however, the sensitivity is partially lowered in comparison with standard SQUID magnetometric methods.

• Frequency of the magnetizing field : ................................................ ( 0.01 - 1 ) Hz
• Adjustable magnetizing field range : ................................................ ( 10^-1 - 10⁵ ) A/m
• Sensitivity with the samples of pellet shape
  with diameter ~12mm and the thickness
  2.5mm at a distance of 11cm : ........................................................... 6x10^-9 Am² Hz^-1/2

The samples have been prepared by our colleagues from the Institute of Inorganic Chemistry.