Abstract:
YBCO is a family of crystalline chemical compounds famous for displaying
high-temperature superconductivity. The structural properties was studied
by using X-ray powder diffraction (XRD), scanning electron microscope
(SEM) and Fourier Transform Infrared (FT-IR). X-ray diffraction analysis
showed that all samples have orthorhombic structures correspond to the high
and low- phase with changing of the lattice parameters, and the crystal
structure for pure YBa2Cu3O7 is found to confirm the phase formation.
Scanning Electron Microscope (SEM) pictures show uniform and
homogeneous distribution, and the effect of the doping of aluminum oxide to
the composite samples decreases the grains of the image of the distortion in
the shape and structure. Fourier Transform Infrared spectrum showed that
the YBa2Cu3O7 is pure, and YBa2Cu3O7 which doped with AL2O3 revealed
perfectly. The optical properties for pure YBa2Cu3O7 and YBa2Cu3O7 which
doped with AL2O3 was studied by using Ultraviolet-Visible
Spectrophotometry (UV/VIS), the transmittance and absorbance spectra
were recorded include the wavelength range of (200-800)nm, the results
showed that Transmittance decreases with increasing in the wavelength
between (200- 300) nm, and then remains constant with increasing
wavelength, and absorbance increased with increasing wavelength between
(200- 300) nm, and then remains constant with increasing the wavelength,
and the Absorption Coefficient, refractive index and extinction coefficient
were also calculated. The optical energy gap decreases with increase the
doping with YBa2Cu3O7 which doped with AL2O3, and also optical
conductivity increases with elevated on absorbance. The electrical properties
studied by using (I-V) measurements, also subjected our sample for (I-V)
V
characterization at different sample through four probe method and able to
measure the critical current density (Jc) and found a decrement of critical
current density with increment of doping, where electrical conductivity was
calculated, the results also showed that The electrical conductivity for pure
YBa2Cu3O7 and YBa2Cu3O7 doped with AL2O3 its increase with increased
the doping concentration.
