1999/12/20 by S.I. Schlachter, S. I. Schlachter, Schlachter, S. I. +20
Engineering · Materials Science · Physics and Astronomy · #FOS: Physical sciences #Magnetic Properties of Alloys #Physics of Superconductivity and Magnetism #Superconducting Materials and Applications #Superconductivity (cond-mat.supr-con) #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.cond-mat/9912357
5 pages with 2 figures, to be published in J. Low Temp. Phys. 117 (3/4) (1999)
arxiv created 1999/12/20 · openalex publication_date 1999/12/20 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We studied Tc of YBa2Cu3Ox (Y123), Y0.89Ca0.11Ba2Cu3Ox (YCa123) and NdBa2Cu3Ox (Nd123) single crystals with various oxygen contents x. Compared to Tc(x) of Y123 the Tc(x) curves of YCa123 are shifted to lower oxygen contents and the maximum transition temperature Tc,max decreases with increasing Ca content whereas in Nd123 Tc(x) is shifted to higher oxygen contents and Tc,max is increased. According to the universal parabolic Tc(nh) behavior the differences in Tc(x)of Y123, YCa123 and Nd123 can be ascribed to different hole concentrations nh in the CuO2 planes caused by doping via changes in chemistry or structure. In order to study the influence of structural changes on Tc we examined the hydrostatic pressure effect dTc/dp (p up to 0.6 GPa). In the underdoped region, at nh=0.11, the examined compounds show a peak in dTc/dp which is very pronounced for systems with well ordered CuO chains. As this peak occurs at the same nh in all investigated systems it is not caused by oxygen ordering, but its origins might be found in a strong influence of lattice deformations on the electronic structure.