Electrical Properties of High-Pressure Metallic Modification of Iodine

Abstract

The electrical resistance up to 250 kbar and down to 1.7 K, and the thermoelectric power up to 250 kbar at room temperature have been measured in iodine using a diamond-anvil cell. The resistance decreases rapidly and continuously with increasing pressure. The resistance anomaly has been found at 225 kbar and room temperature. The resistive characteristic temperature θ in the Grüneisen-Bloch equation is 225 K for metallic iodine at 235 kbar, The thermoelectric power decreases from a large positive value to a small positive one with increasing pressure and is +4±3 µV/deg at 240 kbar. These electrical properties have been discussed in relation to the structural change induced by pressure.