Berlin 2008 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 51: Poster IV
HL 51.32: Poster
Donnerstag, 28. Februar 2008, 16:30–19:00, Poster D
Pressure-induced phase transition in Cu3N — •Komalavalli Thirunavukkuarasu1, Dieter Rau2, Rainer Niewa2, and Christine A Kuntscher1 — 1Experimentalphysik II, Universität Augsburg, D-86159 Augsburg, Germany — 2Department Chemie, Technische Universität München, 85474 Garching, Germany
Cu3N has attracted a lot of attention since the 1980ies because of its possible application prospect as an optical storage medium [1]. Cu3N decomposes into Cu and N2 at temperatures 300 - 470∘C and undergoes a semiconductor-to-metal transition; therefore, it can be used as a write-once optical recording material upon heating. The relatively low decomposition temperature of this compound indicates weak Cu-N bonding and therefore high sensitivity with respect to pressure modifications. Furthermore, the relatively small band gap of 1 eV suggests that a pressure-induced metallization could be induced at modest pressures. Indeed, a semiconductor-to-metal transition induced at around 5 GPa is observed by pressure-dependent resistivity measurements [2,3]. We performed pressure-dependent transmittance measurements on Cu3N powder samples in the infrared-visible frequency range for pressures up to 11 GPa. The evidence for a pressure-induced semiconductor-to-metal transition in the optical properties of this compound is discussed. We acknowledge the ANKA Angströmquelle Karlsruhe for the provision of beamtime and the DFG for financial support.
[1] T. Maruyama et al., Appl. Phys. Lett., 69, 890 (1996).
[2] L. X. Yang et al., Chin. Phys. Lett., 23, 426 (2006).
[3] J. G. Zhao et al., phys. stat. sol (b), 243, 573 (2006).