Contamination from magnetic starting materials in flux-grown single crystals of RFeAsO superconductorsPhysical Review B
AbstractWhile the flux growth often provides the best method for obtaining single crystals of new-novel materials, the process is prone to producing crystals with trapped second-phase inclusions. In the case of NdFeAsO single crystals grown out of NaAs flux under ambient pressure, some crystals show a lambda anomaly in the specific heat curve at ~12 K. This anomaly is missing in other crystals from the same batch. We show that the lambda anomaly at 12 K is from residual NdAs starting material which is mainly on the edges of the crystals. The isothermal magnetization of LaFeAsO at 300 K clearly illustrates the effect of ferromagnetic impurities on the magnetic properties of LaFeAsO crystals.
Copyright OwnerAmerican Physical Society
Citation InformationJ.-Q. Yan, Qingfeng Xing, Brandt A. Jensen, H. Xu, et al.. "Contamination from magnetic starting materials in flux-grown single crystals of RFeAsO superconductors" Physical Review B Vol. 84 Iss. 16 (2011) p. 012501
Available at: http://works.bepress.com/thomas_lograsso/48/