Manifestation of anisotropy in melting systematics of RBa2Cu3O7-delta (R=lanthanides)

作者：Su H B^*; Welch D O; Wong Ng W; Cook L P; Yang Z

来源：Applied Physics Letters, 2007, 91(17): 172510.

DOI：10.1063/1.2799242

The conventional isotropic Debye temperature fails to account for the trend of melting temperatures for the high T-C superconductors, RBa2Cu3O7-delta (R-123), as a function of the ionic radius of R3+. We overcame this problem by calculating Debye temperatures using mean sound velocity along the c axis that features an anisotropic layered structure. Using the "improved" Debye temperature, the trend of derived melting temperatures based on the "Lindemann law" matches well with experimental data. This trend is also confirmed by comparing theoretical and experimental Raman active modes corresponding to the Cu-O (plane copper and apical oxygen) and Ba-O (in-plane) bonds in R-123 series.

• 出版日期2007-10-22
• 单位南阳理工学院