FAR INFRARED REFLECTION MEASUREMENT OF THE ENERGY GAP OF YBa2Cu3O9-δ
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Abstract
The superconducting energy gap of YBa2Cu3O9-δ(Tc=90K) has been measured by means of far infrared reflection spectra. The value of 2Δ /kTc is between 2.2 and 3.4. According to the analysis of the dielectric function derived from K-K relations, we suggest that the energy gap value would be less than 18.8meV( 150cm-1). The temperature dependence of the energy gap Δ(T) is also obtained. -