Effects of Ca and Sr chemical doping on the average superconducting kinetic energy of YBa2Cu3O7-δ

International Conference on Strongly Correlated Electron Systems 2014

Vieira, V.N.^1 ; Mendonça, A.P.A.^1 ; Dias, F.T.^1 ; Hneda, M.L.^2 ; Pureur, P.^2 ; Schaf, J.^2 ; Mesquita, F.^2

Instituto de Física e Matemática, Universidade Federal de Pelotas, UFPEL, C.P. 354, Pelotas

96010-900, RS, Brazil^1

Instituto de Física, Universidade Federal Do Rio Grande Do sul, UFRGS, C. P. 15051, Porto Alegre

91501-970, RS, Brazil^2

关键词: Ceramic samples;    Chemical pressure effects;    DC magnetic field;    DC magnetization;    Kinetic energy density;    SQUID magnetometers;    Superconducting state;    Temperature profiles;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/592/1/012062/pdf
DOI  :  10.1088/1742-6596/592/1/012062

来源: IOP

【 摘 要 】

In this brief communication we applied the MZFC(T) and MFCC(T) reversible dc magnetizations to get the average superconducting kinetic energy density, kS(T,B) of YBa2Cu3O7-δ, Y0.95Ca0.05Ba2Cu3O7-δand YBa1.75Sr0.25Cu3O7-δceramic samples with the aim of study the effects of Ca and Sr doping on the kS(T,B). The MZFC(T) and MFCC(T) measurements were performed with a SQUID magnetometer from quantum design to dc magnetic fields up to 50kOe. The determination of the kS(T,B) from reversible dc magnetization is supported by virial theorem of superconductivity [kS(T,B)= M.B]. The kS(T,B) results show an common temperature profile for all the samples which is smoothly affected by the magnetic field. On the other hand the kS(T,B) results to T > Tccould not be associated to the pseudogap phenomenon. The Ca doping affects more effectively the kS(T,B) behaviour then Sr doping. A possible explanation to this feature could be associated to the fact that the hole doping promoted by Ca doping depress more considerably the superconducting state and enhances the granular character of the YBa2Cu3O7-δsuperconductor than the chemical pressure effect promoted by Sr doping.