Abstract
A strong microwave absorption at low magnetic fields is observed for a variety of metallic cuprates below their critical superconducting transition temperatures (Tc) using conventional electron paramagnetic resonance (EPR) instrumentation. The low-field microwave signal was investigated in the following high-temperature superconductors, YBa2Cu3O7–x(Tc= 95 K), GdBa2Cu3O7–x(Tc= 95 K), YBa2Cu4O8(Tc= 75 K), (Bi1.6Pb0.4)Sr2Ca2Cu3Oy(Tc= 115 K), Pb0.5Bi2Sr2Ca2.5Cu4.5Oy(Tc= 118 K)(Tl0.5Pb0.5)Sr2(Ca0.8Er0.2)Cu2Oy(Tc= 115 K), Tl2Ba2Ca2Cu3Oy(Tc= 118 K), TbTl2Ba2Cu3Oy(Tc= 84 K), Tl2Ba2Ca2Cu3O10(single-crystal, Tc= 118 K) and Bi2Sr2CaCu2O8(single-crystal, Tc= 80 K). We have investigated the usefulness of the technique as a practical non-intrusive method for screening potentially superconducting samples, with particular emphasis on sensitivity, the effect of microwave power and the inherent problems of studying signals at small magnetic fields. In the latter regard, we have also carried out studies using a radiofrequency EPR spectrometer operating at 300 MHz, which facilitated detailed calibration of the 0–200 G region, where the signal is most intense.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of the Chemical Society, Faraday Transactions
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
