The Rubidium Transition at ~ 180°k.

Resistivity measurements have shown the presence of a "transition" in rubidium at ~ 180°K. The nature of this transition has been further investigated by dilatometric and X-ray studies of thermal expansion, thermoelectric force measurements, and X-ray examination for the possibility of a change of crystal structure. Evidence for the transition in properties other than resistance measurements is very variable and, although the transition does not appear to involve a change of crystal structure, its characterization as an electronic change remains obscure. Analysis of resistance measurements shows that the resistive behavior of rubidium above 180°K. must be regarded as anomalous.