Electrical properties of tungsten on silicon carbide (4H-SiC) Schottky diodes are investigated through the analysis of the forward current-voltage (I-V) characteristics measured at elevated temperatures within the range of 303-448 K. The subsequently derived Schottky barrier heights (SBHs) and ideality factors are found to be temperature dependent with distributions that are adequately explained within the framework of the model proposed by Tung in which he considers the barrier at a metal-semiconductor interface as consisting of locally non-uniform but interacting patches of different barrier heights embedded in a background of uniform barrier height. A uniform barrier height of 1.248 eV, a Richardson's constant of 129.95 A cm −2 K 2 and a factor T o of 23.92 K obtained agree very well with values published previously for similar Schottky barrier systems. Therefore, it has been concluded that the temperature-dependent I-V characteristics of the device can be successfully explained with lateral inhomogeneities distribution of the SBH.

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We investigated the athermal high-pressure behavior of the elastic properties of SrTiO3 (STO) up to 26 GPa in cubic, tetragonal and orthorhombic phases using the ab initio pseudo-potential method. Our results for the cubic phase are in good agreement with experiment and previous pseudo-potential calculations. There are no studies for the tetragonal and orthorhombic phases under high pressure available for comparison. To date, there are no global data on elastic parameters under high pressure for STO. We establish data when we report the results of our structural and elastic study under high pressure in the three phases. Our calculations show that the cubic–tetragonal phase transition occurs at 6 GPa and the tetragonal–orthorhombic phase transition at 14 GPa. A third and unknown phase transition from orthorhombic Cmcm to monoclinic P21 /m was observed at 24 GPa, but no study has explored it. The orthorhombic phase is unstable and this instability may be due to ferroelectricity at high pressure. The elastic properties of STO are also strongly pressure dependent with instabilities near the phase transition pressure. STO is more resistant to plastic deformation and to fracture in the cubic phase than in the tetragonal and orthorhombic phases.

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