Stability Region and Synthesis of Single Crystals of Brack Phosphorus -Study on the Synthesis of Inorganic Single Crystals under High Tempera ture and High Pressure. IV.-

Abstract

The stability region and synthesis of single crystals of black phosphorus under high temperature and pressure conditions were studied by using a piston-cylinder type high pressure apparatus. A graphite tube 6.2 mm in diameter and 20 mm long was filled with reagent grade red phosphorus, the starting material.
Red phosphorus was stable below a bout 700°C under 6 kbar, about 550°C under 10 kbar, and about 700°C under 4 kbar. The powdered black phosphorus, in pieces about 5 μm in length, was grown at 700 to 900°C under 6 kbar, and at 600 to 1000°C under 10 kbar (1.01 GPa). The temperature region of liquid phase was about 1000 to 1400°C under 6 kbar, and about 1050 to 1080°C under 10 kbar, Large single crystals of black phosphorus were consistently grown from this liquid phase.
The vapor phase regio n was found at above 1500°C under 6 kbar, above 800°C under 10kbar, and above 700°C under 3 kbar.
The maximum dimension of platy single, crystals of black phosphorus was 4.5 x 0.25 mm²and these plates usually have well-developed shapes and characteristic lustre.