A generalized method of estimation of critical exponents through an indigenous susceptometry setup for YBCO materials

作者：Chakrabarti Arindam^*; Neogy Chirantan

来源：Cryogenics, 2013, 55-56: 35-46.

DOI：10.1016/j.cryogenics.2013.02.003

• Vortex glass transition
• Critical exponents
• YBCO materials
• Susceptometry

The real and imaginary parts of complex susceptibility values of bulk ceramic YBCO materials have been extracted at different frequencies and temperatures by measuring impedances using a single-coil sweptac method. From these susceptibility components, the ac conductivity and its loss angle have been derived numerically. The dynamic and static critical exponents, z and v obtained from the scaling of conductivity loss angle based on FFH's vortex glass (VG) model were found to be in agreement with the values obtained by other workers, in different methods characterizing a continuous phase transition and revealing a stronger correlation in HTS materials. To verify their universality, it has been shown that the exponent values support the scaling features of ac-conductivity (or resistivity) very well and can scale susceptibility also at the proximity of critical temperature. It is highly expected that this simpler and straight forward method of extraction and evaluation of these critical exponents discussed here may be applicable to any other High Temperature Superconductors or other complex materials in bulk form.

• 出版日期2013-6