• T G Ramesh

      Articles written in Bulletin of Materials Science

    • Mercury chalcogenides under pressure

      T G Ramesh V Shubha P S Gopalakrishnan

      More Details Abstract Fulltext PDF

      The mercury chalcogenides, HgTe and Hg1−x Cdx Te, have received considerable attention in recent years because of their use in infrared photon detectors. This article is concerned with some recent experiments on the Γ68 band crossover in these systems induced by pressure. It is shown that although the inverted band model is valid for HgTe, the conclusions of the earlier workers on the pressure induced Γ68 crossover are erroneous. Experimental results show that it is difficult to observe the band crossover due to an intervening structural phase transition from cubic zinc blend to the cinnabar structure. However pressure experiments on the semiconductor alloy system Hg0·9Cd0·1 Te clearly indicate this crossover. New results on the zinc blend-cinnabar phase transformation are also presented. The striking behaviour of thermoelectric power in the high pressure cinnabar phase is correlated with the available experimental data on the structurally similar elemental semiconductors like selenium and tellurium.

    • Pressure-induced band cross-over in Pb1−xSnxTe

      T G Ramesh V Shubha P S Gopalakrishnan

      More Details Abstract Fulltext PDF

      Resistivity and thermoelectric power studies have been carried out on two semiconductor alloy systems viz Pb0·8Sn0·2Te and Pb0·6Sn0·4Te up to 35 kbar pressure. Thermoelectric power and resistivity data on Pb0·8Sn0·2Te indicate that the energy gapEg=EL6EL6+ decreases with pressure resulting in a zero gap state near 35 kbar pressure. TEP studies on the alloy system Pb0·6Sn0·4Te provide direct evidence for a pressure induced L6→L6+ cross over transition.

  • Bulletin of Materials Science | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2017-2019 Indian Academy of Sciences, Bengaluru.