Uranium monochalcogenides

Uranium monochalcogenides. These compounds are all simple ferromagnets. It is reasonable to assume that the muon takes up the (i, j) interstitial position since the same crystal structure prevails and since the lattice constants are not significantly different. As pointed out above, the local field will not cancel at such a high-symmetry site for FM order. The contact field remains, pointing in the direction of spontaneous magnetization. UTe, US and the pseudo-binary system Ui-xUa S were studied by (xSR. 

Fig. 57. The calculated bulk moduli (open squares) of the uranium monochalcogenides (right) and monopnictides (left) compared with measurements. The open circles indicate data from measurements by Holden et al. (1982), Vedel et al. (1986), Neuenschwander et al. (1984), Buyers et al. (1983), Jackman et al. (1986), Olsen et al. (1984) and DuPlessis et al. (1985) for the chalcogenides and from Guinan and Cline (1972), Padel et al. (1970), Van Doom and DuPlessis (1977), Fournier et al. (1980), Leger et al. (1986, 1988), Stirling et al. (1983) and Neuenschwander et al. (1986) for the pnictides. More details of the measurements are given by Gerward et al. (1989) and Olsen et al. (1989), from which the filled-circle data points are taken.

Haessler, M., De Novion, C.-H., Damien, D., Electronic stracture of mixed uranium-thorium monochalcogenides, Plutonium 1975 and other actinides, Proc. Symp. Baden Baden, Germany, Sept. 10-13, 1975, pp.649-657, (1976). Cited on page 306. 

Fig. 17. Ordered magnetic moments and ordering temperatures of uranium monopnictides and monochalcogenides as a function of the lattice constant The U-U separation is simply tZ(,/ /5. The ordering temperatures are indicated by the right-hand scale and marked as solid circles. The values of the ordered moments are indicated by the left-hand scale and marked with solid squares. (From Buyers and Holden 1985.) Note that this figure appeared also in many earlier works.

Reason (b), which was the driving scientific reason for studying these systems is now recognized to be much more complex. Divalent uranium or other actinide species are almost impossible to stabilize, and so are not expected. Numerous studies, see the reviews byS choenes (1984), Brooks et al. (1984), and Baer (1984), have shown that all the monopnictides and monochalcogenides (and thus all the solid solutions as well) are essentially semimetals. It is generally accepted that the monopnictides are... 

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