標題: | The high-pressure synthesis and characterization of some praseodymium-substituted rare-earth based R2Ba4Cu7O14+delta (R = Nd, Sm, Eu, Gd, Ho, Tm) |
作者: | Chen, TM Lai, YL Kao, FS 交大名義發表 應用化學系 National Chiao Tung University Department of Applied Chemistry |
公開日期: | 1-八月-1997 |
摘要: | Samples of the (R1-xPrx)(2)Ba4Cu7O14+delta (R = Nd, Sm, Eu, Gd, Ho, Tm; Pr-doped R247) systems with x = 0 to 1.0 and with an increment of 0.1 in x was investigated. Single-phased samples were obtained with substitution limit equal to 0.4, 0.6, 0.5, 0.6, 0.8 and 0.5 for phases with R = Nd, Sm, Eu, Gd, Ho and Tm, respectively, as indicated by x-ray diffraction (XRD) data. T-c's of the Pr-doped R247 phases were found to be suppressed from 66, 69, 75, 70, 92 and 88K down to 41K (x=0.3), 20 K (x=0.4), 52K(x = 0.4), 18K (x = 0.5), 8K (x = 0.7) and 50K (x = 0.4) and the corresponding composition coefficients of T-c, dT(c)/dx, were found to be -41.3, -50.4, -28.0, -47.7, -53.0 and -46.0 K/Pr-atom per formula unit for Pr-doped R247 phases with R = Nd, Sm, Eu, Gd, Ho and Tm, respectively. The variation of T-c and dT(c)/dx coefficients ofthe Pr-doped R247 phases upon Pr doping are described and their implcations are discussed. |
URI: | http://hdl.handle.net/11536/394 |
ISSN: | 0921-4534 |
期刊: | PHYSICA C |
Volume: | 282 |
Issue: | |
起始頁: | 789 |
結束頁: | 790 |
顯示於類別: | 會議論文 |