%e report measurements of the magnetization of insulating phosphorus-doped silicon for fields up to 50 ko and temperatures down to 1.25 K, for dopant concentrations N =6.7X10" to 2.8)(10' cm . The data are found to be in quantitative agreement with a generalization, to finite fields, of a scaling calculation of the magnetic properties of the insulating phase, and support a model of hierarchically coupled spin pairs.

No abstract

Magnetic-susceptibility, magnetic-anisotropy, and nuclear-magnetic-resonance measurements were performed on single-crystal scandium samples from 4.2 to 300°K. The susceptibility of single-crystal scandium is greater along the a axis than along the c axis. The nuclear relaxation rate {TiT)~l has a sin 2 0 dependence on the angle between the static magnetic field and the crystallographic c axis. The orbital hyperfine interaction is the major contribution to the relaxation rate. From the experimental results, values are estimated for the electronic density of states, the average fractional s character, the average fractional admixture coefficients for d electrons at the Fermi surface, and the orbital paramagnetism.12

The resistivity and the Hall coefficient of indium-doped cadmium selenide with carrier concentrations spanning the insulator-to-metal transition have been measured as a function of temperature. We demonstrate that use of the Hall mobility deduced from these data and careful analysis and application of recent theory yield an estimate of the degree of compensation, E =N& /ND, for metallic as well as insulating material. Combining these results with Hall coefficient measurements at room temperature, one can then estimate both the number of donors, ND, and acceptors, N&.Samples were cut with their faces perpendicular to the c axis to a size of approximately 3)&4&(0.8 rnrn . Using the van der Pauw' method, the resistivity and the Hall coefficient were determined both at room temperature, and in a cold-finger cryostat between 8 and 80 K.

No abstract