Synthesis and Experimental Studies on YbFe2As2 Iron Pnictides

Abstract

The iron-based superconductors system is the first of its kind using magnetic newlinematerials in the context of high-temperature superconductors with a critical newlinetemperature above 50 K. Other Fe based similar compounds have also revealed the newlinepresence of such high Transition Temperature (Tc) superconductors. Many research newlinegroups have been intensively pursuing on the complicated nature of the interplay newlineamong magnetism and pnictides superconductor including 1111 type of LaFeAsO, newlineSmFeAsO, PrFeAsO, etc., 111 type of LiFeAs, NaFeAs, LeFeP, etc., and 122 newlinetype of BaFe2As2, SrFe2As2, CaFe2As2, etc. Among these pnictides, a new class of newlinecompound in 122 type pnictides is YbFe2As2 crystals attracting greater importance in newlineour study. This new compound of YbFe2As2 crystals were synthesized by melt growth technique and/or flux free growth technique. The resultant compound was investigated by the method of powder X-Ray Diffraction (XRD) analysis, Energy Dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), magnetic and conductivity measurements to test for superconductivity. The detailed crystal structure of YbFe2As2 crystals were analysed by Rietveld refinement by using FullProf software. Furthermore, the magnetic characteristic of the resultant compound were characterized by using superconducting quantum interference device (SQUID) analysis. The effect of oxygen adsorption and aging of BaFe2As2 crystals along with comparative studies on the impact of adsorbed oxygen by YbFe2As2 and BaFe2As2 crystals have been studied. Magnetotransport measurement and scaling have been studied for YbFe2As2. The verification of Kohler s rule and investigations on surface chemical composition of YbFe2As2 crystals by X-ray photo electron spectroscopy measurement have been carried out. Finally, it was ascertained that the calculation of the electronic structure ison the basis of the Density Functional Theory (DFT) technique through Vienna ab newlineinitio simulation package (VASP). A experimental and theoretical investigation