Contamination from Magnetic Starting Materials in Flux-grown Single Crystals of RFeAsO Superconductors
| Title | Contamination from Magnetic Starting Materials in Flux-grown Single Crystals of RFeAsO Superconductors |
| Publication Type | Journal Article |
| Year of Publication | 2011 |
| Authors | Yan J-Q, Xing Q, Jensen B, Xu H, Dennis KW, McCallum RW, Lograsso TA |
| Journal Title | Physical Review B |
| Volume | 84 |
| Pages | 012501 |
| Date Published | 07/06 |
| Abstract | While 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. |
| DOI | 10.1103/PhysRevB.84.012501 |
