Flux requirements for the growth of RFeAsO (R = rare earth) superconductors
Millimeter-sized LaFeAsO single crystals have been successfully grown out of NaAs flux starting with (LaAs+1/2Fe{sub 2}O{sub 3}):20NaAs. The factors which allow the growth of these crystals out of NaAs but not out of many other fluxes, such as FeAs, have been investigated. X-ray powder diffraction found that NaAs synthesized for the growth of RFeAsO superconductors has monoclinic LiAs structure. Thermal analysis confirmed that NaAs melts congruently at about 600 C. The ability to extract RFeAsO crystals from this NaAs flux suggests that NaAs has a significant oxygen solubility, possibly due to the formation of the ternary compound NaAsO{sub 2}, and enough oxygen diffusivity to transport solute to the growth front. Oxygen solubility and diffusivity are two important factors in searching for an alternative environmentally benign flux for the growth of RFeAsO superconductors.
- Research Organization:
- Ames Lab., Ames, IA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC02-07CH11358
- OSTI ID:
- 1025209
- Report Number(s):
- IS-J 7598; TRN: US201120%%320
- Journal Information:
- Applied Physics Letters, Vol. 98, Issue 7
- Country of Publication:
- United States
- Language:
- English
Similar Records
Synthesis and structural, magnetic, thermal, and transport properties of several transition metal oxides and aresnides
In situ high energy x-ray synchrotron diffraction study of the synthesis and stoichiometry of LaFeAsO and LaFeAsO[subscript 1-x] F[subscript y]