Electrical data from Hall measurements

Table I. Electrical Data from Hall Measurements on Selected SLS Samples...

Inasmuch as the electrical resistivity peak appeared in the cooling half of the resistivity curve from incomplete cycle was not matched by any such change in the Hall coefficient measurement, the afore mentioned circumstances apply. Consequently, the band structure of TiNi can be regarded as either a simple single band or one positive band dominating over the others in the temperature being considered. This conclusion did have the support of the transport data obtained independently by other investigator [38]. 

Detailed reports of n-type Si-doping of AlxGai.xN were also limited until recently. Details of the electrical and other properties of these doped films are usually limited to a few selected carrier concentrations and alloy compositions. Murakami et al [10] achieved Si-doping of Alo.1Gao.9N by MOVPE with carrier concentrations of 6 x 1017 and 2 x 101 cm 3, with mobilities (calculated from resistivity data) of 40 and 180 cm2/V s. Khan et al [11] also demonstrated MOVPE growth of Alo.09Gao.91N doped with silicon. Hall-effect measurements of these films revealed a mobility of 35 cm2/V s and a donor concentration of 5 x 101 cm 3. 

The electrical resistivity of Na W03, Li WOs, and K WOg has been measured at 300° K. The range of x values was 0.25 < x < 0.9. All resistivities were characteristic of a metal and lie on a single curve. Extrapolation of the conductivity curve to zero conductivity indicated that the tungsten bronzes should be semiconductors for x < 0.25. The resistivities measured for tungsten bronzes with x < 0.25 showed semiconducting behavior. The resistivity of Li WOg exhibited an anomalous peak in the p vs. T curve. The Hall coefficient of Li0 37WO3 indicated one free electron per alkali atom, as previously found for Na WOg. The Seebeck coefficient of Na WOg depended linearly on x 2/3, as expected from free electron theory. The implications of these and other data are discussed. 

---