金属間化合物HgTeの<I>P</I>-<I>T</I>-<I>X</I>状態図と電気的性質

Abstract

The electrical properties of an intermetallic compound HgTe, such as carrier concentrations Ne and Nh, and mobilities μe and μh of electron and hole, respectively, obtained from the analysis of the Galvano-magnetic effects at 4.2 K were thermodynamically associated with the annealing temperature and the partial pressure of Hg on the P(pressure)-T(temperature) phase diagram for the Hg-Te system. The P-T-X(composition) phase diagram of HgTe was drawn from the relative difference |Ne−Nh| and the intrinsic boundary was obtained from the minima of the |Ne−Nh|. Then, the i-boundary of the present work was compared with those reported previously and examined.Also, contour maps of the electron mobility μe and hole mobility μh were drawn on the P-T diagram, which was named, so to speak, P-T-μ(mobility) phase diagram and gave the condition to obtain a desired mobility. Further, the quantities α=μh⁄μe(=1⁄b) and β=Nh⁄Ne, defined in the analysis of the Galvano-magnetic effects of HgTe, were calculated and maps of distribution of these quantities were drawn on the P-T diagram.They were named the P-T-b(=1⁄a) and P-T-β phase diagram, as they represented supplementally the meaning of the P-T-μ and the P-T-X diagram.Additionally, the field of appearance or reversal of the negative or positive sign of Hall coefficient was shown on the P-T diagram, according to conditions of the temperature and the magnetic field in the measurement of Hall coefficient. This diagram is expected to become a reference or a standard to select the condition of the measurement and to estimate a conductive type etc.