With the development of the technique of preparing thin film, artificial superlattices of high-T<sub>c</sub>oxides, especially （YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7</sub&...With the development of the technique of preparing thin film, artificial superlattices of high-T<sub>c</sub>oxides, especially （YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7</sub>）<sub>n</sub>/（PrBa<sub>2</sub>Cu<sub>3</sub>O<sub>7</sub>）<sub>m</sub>, have attracted much attention due to the possibilities of studying a variety of superconducting physical properties otherwise inaccessible. One of the many interesting characteristics of this system is the reduction of T<sub>c</sub> with increase of the thickness of the PrBCO layer in superlattices with thin YBCO layer, which has been observed by many groups. Several theoretical models have been proposed to account for this interesting phenomenon, including a spin polaron model,展开更多
We have fabricated M doped (M = Al, Co, Fe, Ga, Ni and Zn) PrBa2Cu3O7 (PBCO), i.e. PrBa2(Cu1-xMx)3O7. The doping levels x are 0.05, 0.10, 0.15, and 0.20. X-ray data indicated no significant second phase for substituti...We have fabricated M doped (M = Al, Co, Fe, Ga, Ni and Zn) PrBa2Cu3O7 (PBCO), i.e. PrBa2(Cu1-xMx)3O7. The doping levels x are 0.05, 0.10, 0.15, and 0.20. X-ray data indicated no significant second phase for substituting Cu by Al, Co, Fe and Ga up to 20%. However impurity phases were detected for Ni and Zn substituted samples with doping levels equal to and higher than 15%. At 77 K the electrical resistivity of these compounds is orders in magnitude higher than that of PBCO. We also found that although the lattice parameters in the doped samples differ from PBCO, all samples remain orthorhombic. The lattice parameters of the doped sample are very close to those of YBa2Cu3O7-δ (YBCO) and PBCO. For this reason these compounds are better materials to be used as the I-layer for YBCO SIS junctions. Results of structural and transport studies on 2000 thick PrBa2[Cu0.80G0.2]3O7 (PBCGO) and YBCO/PBCGO multilayers are presented in this paper.展开更多
文摘With the development of the technique of preparing thin film, artificial superlattices of high-T<sub>c</sub>oxides, especially （YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7</sub>）<sub>n</sub>/（PrBa<sub>2</sub>Cu<sub>3</sub>O<sub>7</sub>）<sub>m</sub>, have attracted much attention due to the possibilities of studying a variety of superconducting physical properties otherwise inaccessible. One of the many interesting characteristics of this system is the reduction of T<sub>c</sub> with increase of the thickness of the PrBCO layer in superlattices with thin YBCO layer, which has been observed by many groups. Several theoretical models have been proposed to account for this interesting phenomenon, including a spin polaron model,
文摘We have fabricated M doped (M = Al, Co, Fe, Ga, Ni and Zn) PrBa2Cu3O7 (PBCO), i.e. PrBa2(Cu1-xMx)3O7. The doping levels x are 0.05, 0.10, 0.15, and 0.20. X-ray data indicated no significant second phase for substituting Cu by Al, Co, Fe and Ga up to 20%. However impurity phases were detected for Ni and Zn substituted samples with doping levels equal to and higher than 15%. At 77 K the electrical resistivity of these compounds is orders in magnitude higher than that of PBCO. We also found that although the lattice parameters in the doped samples differ from PBCO, all samples remain orthorhombic. The lattice parameters of the doped sample are very close to those of YBa2Cu3O7-δ (YBCO) and PBCO. For this reason these compounds are better materials to be used as the I-layer for YBCO SIS junctions. Results of structural and transport studies on 2000 thick PrBa2[Cu0.80G0.2]3O7 (PBCGO) and YBCO/PBCGO multilayers are presented in this paper.
