SEMICONDUCTING REGION OF YTTERBIUM
The resistivity of elemental Yb at room temperature rises, by a factor of 11, to a maximum at a pressure of 40 kilobars; a further increase in pressure causes a polymorphic transition; the new phase has a resistivity 80% of that of the metal at 1 atmosphere. In the temperaturepressure diagram, the phase boundary has a negative slope. The phase boundary, determined from --190 to 360 c- C, is a straight line that may be extrapolated nearly to the known alpha - materials at transition at 1 atm. Between the transition pressure and 20 kbar, the lowest pressure at which the measurements were made, Yb behaved as a semiconductor. The temperature coefficient of resistance is negative; at constant pressure, the resistivity shows the exponential temperature dependence characteristic of a semiconductor. The parameter in the exponential would correspond to an energy gap 0.015 ev at 20 kbar, an increase with pressure to a maximum of 0.080 ev at 37 kbar, and then a decrease to 0.05 ev at 45 kbar. (auth)
- Research Organization:
- Univ. of California, Berkeley
- NSA Number:
- NSA-17-025817
- OSTI ID:
- 4672265
- Report Number(s):
- UCRL-10715
- Journal Information:
- Science See Saiensu, Journal Name: Science See Saiensu Vol. Vol: 140; ISSN SIENDS1
- Country of Publication:
- United States
- Language:
- English
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