616 research outputs found
Single-crystal growth of the ternary BaFeAs phase using the vertical Bridgman technique
Ternary Ba-Fe-As system has been studied to determine a primary
solidification field of the BaFeAs phase. We found that the
BaFeAs phase most likely melts congruently and primarily solidifies
either in the FeAs excess or BaAs excess liquid. Knowing the
primary solidification field, we have performed the vertical Bridgman growth
using the starting liquid composition of BaFeAs. Large
single crystals of the typical size 10x4x2 mm were obtained and their
quality was confirmed by X-ray Laue and neutron diffraction.Comment: Submitted to Jpn. J. Appl. Phys.; revise
Whirling spin order in the quasicrystal approximant AuAlTb
Neutron powder diffraction experiment has been performed on the quasicrystal
approximant AuAlTb, a body-center-cubic crystal of
icosahedral spin clusters. The long-range antiferromagnetic order was confirmed
at the transition temperature K. The magnetic structure
consists of noncoplanar whirling spins on the icosahedral clusters, arranging
antiferroic-manner. A simple icosahedral spin-cluster model with uniaxial
anisotropy accounts well the whirling spin order as well as the in-field
metamagnetic transition, indicating that the icosahedral symmetry is essential.Comment: 6 pages, 4 figure
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