The cooling rate effect on structure and flux pinning force of FeTeSe single crystal deposited by self-flux method

Abstract

Synthesis and characterization of FeTe0.5Se0.5 single crystals prepared by self-flux technique with two different cooling rates of 1.45 and 5.83 a"integral/h have been investigated. The XRD results show that the samples have tetragonal structure. The SEM results indicate that the samples demonstrate a terrace-like formation. The superconducting transition temperatures of two samples obtained as magnetization measurement are seen to be 14.62 and 14.38 K for sample A (5.83 a"integral/h) and sample B (1.45 a"integral/h), respectively. The M-H curves reveal the existence of ferromagnetism in all measured temperatures. The normalized pinning force f(F-p/F-pmax) at h(H/H (irr) ) curves are scaled using the Dew-Hughes model given by f(h) = Ah (p) (1 - h) (q) with A = 2.73, p = 0.81 and q = 0.69, the ratio [p/p + q] ae 0.54 for cooling rate of 5.83 a"integral/h sample.