Easy basal plane

Fig. 41. The high-field magnetization curves for HOjCon at 4.2 K measured along the three crystallographic directions (the [120] axis is the easy axis of the easy basal plane). Symbols +, [100] axis x, [120] axis open circles, [001] axis full lines are the calculated curves (after Sinnema et al. 1987).

The field d endencies of Ea and Ei, were measured for a Tbo sDyo.s single crystal by Kataev et al. (1989c). Like Tb and Dy this alloy is a helical antiferromagnet with an easy basal plane (Bykhover et al. 1990). The field behavior of Ei, and Ea in the HAFM phase is analogous to that observed for C33 in Dy and Tb by Isci and Palmer (1978) and files et al. (1984) (see fig. 28). The magnetic phase diagram H T) of Tbo.5Dyo,5 constructed... 

Of the 12 slip systems possessed by the CCP stmcture, five are independent, which satisfies the von Mises criterion. For this reason, and because of the multitude of active slip systems in polycrystalline CCP metals, they are the most ductile. Hexagonal close-packed metals contain just one close-packed layer, the (0 0 0 1) basal plane, and three distinct close-packed directions in this plane [I I 2 0], [2 I I 0], [I 2 I 0] as shown in Figure lO.Vh. Thus, there are only three easy glide primary slip systems in HCP metals, and only two of these are independent. Hence, HCP metals tend to have low... 

It can therefore be accepted that whether it is in the natural crystalline form or in a consolidated film, the friction of molybdenum disulphide is adhesive friction, and its low magnitude is due to the easy shear between adjacent lamellae which is made possible by the unusually favourable crystal and electronic structure. However, it must be remembered that the correct orientation of the crystallites is essential for the maintenance of low friction. The shear strength is low only parallel to the basal plane of the lamellae. In other directions the shear strength is high, so that the coefficient of friction will also be high . ... 

Intercalation of graphite by arsenic pentafluoride had been reported in 1975, by Lin Chun-Hsu et al. In 1977, E. R. Falardeau et al. reported that graphite fully intercalated by AsFs, had a basal-plane specific conductivity akin to copper metal. I had already pondered on the reasons for the easy intercalation of graphite by AsFs and had wondered if removal of electrons from the 7r-electron band of graphite was involved. 

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