ISSN:
1573-7357
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The Variation of the transition temperature Tc of YBa2Cu3Ox with hydrostatic He-gas pressure depends on the oxygen content x. The pressure effect dTc/dp increases from small negative values at x=7 to dTc/dp=7.4 K/GPa at x=6.7. For oxygen contents below x=6.7 dTc/dp drops to 3 K/GPa and remains nearly constant1. The charge transfer model2 cannot explain the drop at x=6.7. Thermal expansion measurements on YBa2Cu3Ox indicated that the uniaxial pressure effects along the three crystal axes are different3,4 To investigate the uniaxial pressure effects inductively an experimental setup was constructed. The Tc-change of several YBa2Cu3Ox single crystals with different oxygen contents has been investigated under pressure along the c-axis. To avoid oxygen ordering processes the samples were held below 105 K during the measurements. The results of uniaxial pressure measurements in c-axis direction fit to former uniaxial pressure data3,4,5 and are explained within the charge transfer model. Hydrostatic pressure data12 of overdoped samples fit to the same curve. However, this is not the case for underdoped samples. From this we conclude that only a part of the hydrostatic pressure effect can be explained by charge transfer in the underdoped region. The remaining part can be ascribed to uniaxial pressure effects along the a- and b-axis.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00753893
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