ISSN:
1572-9540
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The (La,Eu(2 CuO 4 system shows superconductivity by dopingCe orSr. Carriers inT′-phase doped withCe are electrons and those inT *-phase doped withSr are holes. In this work,151 Eu Mössbauer analysis is applied for theT′-phase(La 1−x Eu x)2−y Ce y CuO 4 and theT *-phase(La 1−x Eu x)2−y Sr y CuO 4 in order to compare the electronic state and the lattice vibration ofEu in these superconductors. In addition, correlations betweenT c and Mössbauer parameters are examined. The isomer shift of151 Eu is 0.784–0.840 mm/s in theT *-phase and 0.689–0.733 mm/s in theT′-phase, which shows that the lanthanide in these superconductors is tri-valent. The Debye temperature of151 Eu is 180–208 K in theT *-phase and 160–192 K in theT′-phase. The difference of isomer shift between these two phases is explained by theEu−O distance. For(La 1−x Eu x)2−y Ce y CuO 4, a light correlation betweenT c and the Debye temperature is observed, which means the importance of the lattice vibration in high-Tc superconductivity.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02397542
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