GALVANOMAGNETIC PROPERTIES OF URANIUM MONOSULFIDE

The magnetic and galvanomagnetic properties of US, including resistivity, magnetoresistance, and Hall effect, were studied. The resistivity was found to be approximately a hundred times higher in US than in the common ferromagnetic metals, but the temperature dependence of resistivity was similar, showing an abnormal decrease below the Curie point. The magnetoresistance of US was found to be negative with a sharp minimum at the Curie point. The study of the Hall effect revealed that two Hall coefficients could be identified. The extraordinary Hall coefficient, which is related to the magnetization of the material, was found to be proportional to the second power of the resistivity. The ordinary Hall coefficient R/sub o/, related to the applied field, was found to be positive and temperature dependent, with a maximum near the Curie point. The temperature dependence of R/sub o/ constituted the biggest dissimilarity between US and other ferromagnetic substances. The effective carrier concentration evaluated from this coefficient was 0.45 hole per atom at absolute zero. The study of the magnetic properties yielded values of the saturation magnetization at various temperatures which indicated that at absolute zero the atomic moment is 1.05 plus or minus 0.03 Bohr magnetons. These results are correlated with a band picture based on overlapping 7s and 5f bands. (auth