Electronic Material Properties - und Geowissenschaften ...

Recent Advances in New Hard High-Pressure Nitrides
Andreas Zerr 1 , Ralf Riedel 1 , Toshimori Sekine 2 , J. E. Lowther 3 , Wai-Yim
Ching 4 , Isao Tanaka 5
1 Institut für Materialwissenschaft, TU Darmstadt, Petersenstr. 23, 64287 Darmstadt, Germany
2 Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba 305-0044, Japan
3 DST-NRF Center of Excellence in Strong Materials and School of Physics, University of the Witwatersrand,
P. O. Wits, 2050, Johannesburg, South Africa.
4 Department of Physics, University of Missouri-Kansas City, Kansas City, Missouri, 64110, USA
5 Department of Materials Science and Engineering, Kyoto University, Yoshida, Sakyo, Kyoto 606-8501
Japan.
Since the discovery of spinel nitrides in 1999, there is presently much effort in basic
science to further develop advanced nitrides and electronic nitrides. Aim and scope of the
research in this field is to synthesize novel nitrides for structural and functional
applications. Silicon-based spinel nitrides combine ultra-high hardness with high thermal
stability in terms of decomposition in different environments and are expected to show
interesting optoelectronic properties. These features make spinel nitrides suitable for
applications as cutting tools and light emitting diodes, respectively. The ultra-high pressure
and temperature synthesis of spinel silicon nitride and germanium nitride on the one hand
as well as the successful synthesis of tin nitride at ambient pressure on the other hand
have caused an enormous impact on both basic science and technological development of
advanced nitrides. Moreover, the novel phases of transition metal nitrides like Zr3N4 and
Hf3N4 with Th3P4 structure as well as the recently published mono nitrides of Pt or Mo
demonstrate the scientific potential of high pressure synthesis techniques in the field of
materials science. Here, the state of the art and the progress in the field of novel hard
materials based on nitrides and produced under high pressure are reviewed.
Fig. 1: Spinel-type structure of γ-Si3N4 (left) with calculated electronic band structure (right).
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