Pressure-Temperature Phase Diagram of Bismuth at Low Temperatures

The phase boundaries in bismuth were studied below room temperature to 45 k under pressures up to 50 kbar by electrical resistance measurements. The bismuth II-III phase transition was observed below 160 K during both compression in isothermal experiments and increase of the temperature in isobaric experiments. The temperature coefficient of the bismuth I-II transition pressure below room temperature to 77 K was determined to be -4×10 -2 kbar/K. The resistance change reported to be a new transition of bismuth at low temperatures by Il'ina and Itskevich was not found in accord with Roux, Andreani and Rapin, Holzapfel and Severin, and Compy. Recent results by other authors on the phase diagram of bismuth to 90 kbar and 800 K are summarized and discussed with the present result.