TITLE:
Influence of Ca Content on Binding Energy and Cooper Pairing in Y1-xCaxBa2Cu3O7-δ Compound
AUTHORS:
Bassam M. Mustafa, Abbas H. Rostam
KEYWORDS:
Superconductor Binding Energy, Formation of Cooper Pairing, Cooper Pairing in HTSC
JOURNAL NAME:
World Journal of Condensed Matter Physics,
Vol.5 No.1,
February
16,
2015
ABSTRACT: In this
research, the influence of calcium content on the binding energy and Cooper pairing
is investigated for the high temperature superconducting Y1-xCaxBa2Cu3O7-δ compound where x = 0 - 0.2). This is done by using
model considering that the formation of Cooper pairs happens during tunneling
mechanism of holes between the two CuO2 layers in the YCBCO crystal
which are considered as forming adjacent potential wells. In this work, we make
some modifications on the mentioned model and a modified equation for the
binding energy as a function of Ca concentration is formulated to study the
effect of Ca content by considering the change in the distance between the CuO2 layer as a function of Ca. The calculated results agree very well with
experimental results. This happens because the Ca2+ substitution for
Y3+ leads to decreasing the distance between the two CuO2 layers and hence potential energy of the system will be decreased. This leads
to decreasing the binding energy between the Cooper pairs, and decreasing the
distance between the two CuO2 layers increasing the tunneling
probability of holes between the two CuO2 layers and thus increasing
conduction mechanism and thus increasing current density, but this will
decrease the energy gap and as a result decrease the critical temperature. The
calculated results agree very well with experimental results.