β Scribed by Hiroshi Nozaki; Masanobu Saeki; Mitsuko Onoda
No coin nor oath required. For personal study only.
Two types of compound in (\mathrm{BaTa}{2} \mathrm{~S}{5}) were specified according to their physical properties and superiattice arrangements. Electrical resistivity and ac magnetic susceptibility measurements indicate that both compounds are superconducting with transition temperatures (T_{c}=2.88) or (3.14 \mathrm{~K}), respectively, being dependent on formation processes of the specimens. The normal state properties, such as resistivity, Hall coefficient, magnetoresistance, and magnetic susceptibility, are also different between the two types of compound. Especially, magnetic susceptibility for the one type with lower (T_{\mathrm{c}}) shows a Curie-Weiss-type paramagnetism below about (50 \mathrm{~K}), while that with higher (T_{\mathrm{c}}) shows a temperature independent paramagnetism with a clear cusp at (70 \mathrm{~K}). Electron diffraction experiments show that the superlattice of the former compound is (a \sqrt{28} \times a \sqrt{28} \times n c), while the structure of the latter consists of two types of superlattice which stack alternatively along the (c) axis. 1995 Academk Press, , snc.
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