Polymorphous GdScO 3 as high permittivity dielectric

Autor: A. Besmehn, J. Schubert, K. Rahmanizadeh, Gang Niu, Gustav Bihlmayer, Martina Luysberg, S. Mantl, M. Schnee, T. Schroeder, Martin Mikulics, A. Fox, Hilde Hardtdegen, F. Wendt, A. Schäfer
Rok vydání: 2015
Předmět:
Zdroj: Journal of Alloys and Compounds. 651:514-520
ISSN: 0925-8388
Popis: Four different polymorphs of GdScO 3 are assessed theoretically and experimentally with respect to their suitability as a dielectric. The calculations carried out by density functional theory reveal lattice constants, band gaps and the energies of formation of three crystal phases. Experimentally all three crystal phases and the amorphous phase can be realized as thin films by pulsed laser deposition using various growth templates. Their respective crystal structures are confirmed by X-ray diffraction and transmission electron microscopy reflecting the calculated lattice constants. X-ray photoelectron spectroscopy unveils the band gaps of the different polymorphs of GdScO 3 which are above 5 eV for all films demonstrating good insulating properties. From capacitance voltage measurements, high permittivities of up to 27 for hexagonal GdScO 3 are deduced.
Databáze: OpenAIRE