THE TWO HALL EFFECTS OF IRON-COBALT ALLOYS
Abstract
The Hall coefficients and resistivities of the Fe-Co alloys were measured at 77 K, 169 K, and room temperature using fields up to 3.3 weber/m2. For less than O.2 deg/deg Co in Fe the ordinary Hall coefficient R(sub0)* is positive at room temperature and negative at low temperatures; for all other compositions R(sub0)*t is negative. Analysis with a simple band model shows that, as iron is added to cobalt, one half of the 3d band remains filled for up to 20 deg/deg Fe. It then empties, having about 0.2 holes per atom at 50 deg/deg Fe. At 65 deg/deg Fe the bands apparently shift so that again one 3d sub-band is filled. The extraordinary Hall coefficient R(sub 1)* is positive for less than 25 deg/deg Co in Fe, but for all other compositions it changes from positive to negative as the temperature decreases from 300 K to l69 K. R(sub 1)* and the resistivity rho are related by R(sub 1)* = a + b(rho-sq). The influence of the approach to magnetic saturation on the Hall curves is examined in detail. The Hall effect is not very useful for studying the approach to saturation, but magnetic data can be used to calculate corrections to R(sub 0)* and R(sub 1)*.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 31, 1958
- Accession Number
- AD0210651
Entities
People
- Emerson M. Pugh
- Frank P. Beitel Jr.
Organizations
- Carnegie Institute of Technology