Excess conductivity and AC susceptibility studies of Y-123 superconductor added with TiO2 nano-wires


Hannachi E., Slimani Y., Ekicibil A. , Manikandan A., Ben Azzouz F.

MATERIALS CHEMISTRY AND PHYSICS, cilt.235, 2019 (SCI İndekslerine Giren Dergi) identifier identifier

Özet

We have studied the impact of TiO2 nano-wires (NWs) used as additives on inter-granular and intra-granular coupling of YBa2Cu3O7-d (noted YBCO or Y-123) superconductor. Series of YBCO/(TiO2)(x) with 0 <= x <= 1 wt% were made by solid-state reaction process. The crystal structure, morphology, microstructure and chemical compositions were methodically investigated using X-ray diffraction (XRD), scanning electron (SEM) and transmission electron (TEM) microscopes along with EDX system. XRD showed the obtaining of single YBCO orthorhombic phase for all samples. SEM and TEM observations revealed the occurrence of NWs dispersed among grains inducing inhomegenties and intergrowth of defect regions on YBCO/(TiO2) composite. The excess conductivity of YBCO/(TiO2)(x) superconductors were examined from the resistivity against temperature results. The examination indicated that the addition of TiO2 NWs led to the change in dimensional in the electrical properties and enhancement of physical parameters. The 0.1 wt% TiO2 added sample showed a dominance of 3D fluctuation regime and higher critical current density J(c)(0) among all samples. AC-susceptibility were done using physical properties measurement system (PPMS). The detailed analysis confirmed the strengthening of inter-granular coupling of YBCO with the addition of small amount of TiO2 NWs. The inter-granular current density (J(c,inter)(0)) was shown to be the highest in 0.1 wt% added sample.