Solid state synthesis and characterization of bulk FeTe0.5Se0.5superconductors

İngilizce (OpenAlex)

FeTe 0.5 Se 0.5 polycrystalline superconductor samples were synthesized by solid- state reaction method at different heating temperatures. The morphological and structural characterization of FeTe 0 5 Se 0.5 samples were carried out by X-rays Diffraction, Scanning Electron Microscope and Energy Dispersive X-ray Spectroscopy. The electrical, magnetic and thermal transport properties were investigated up to 8 T by using physical property measurement system. The results reveal that the sensitivity of electrical and magnetic properties strongly depends on the heat treatment cycles. The upper critical field, H c2 (0) , was determined with the magnetic field parallel to the sample surface. It gives a maximum value of 36.3 T. The lower critical field, H c1 (T) , was obtained as 210, 140 and 70 Oe at 5, 8 and 12 K, respectively. The coherence length, ξ , at the zero field, was calculated to be 1.94 nm and suggested a transparent intergrain boundaries peculiarity. The μ 0 H c2 (0)/k B T c rate shows higher value (3.36 T/K) than the Pauli limit (1.84 T/K) which suggests unconventional nature of superconductivity for the polycrystalline FeTe 0.5 Se 0.5 superconducting samples.