Amorphous to fcc-polycrystal transition in Ge{sub 2}Sb{sub 2}Te{sub 5} thin films studied by electrical measurements: Data analysis and comparison with direct microscopy observations

Journal Article · Wed Apr 15 00:00:00 EDT 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3093915· OSTI ID:21356111

La Fata, Pietro; Torrisi, Felice; Lombardo, Salvatore; Nicotra, Giuseppe; Puglisi, Rosaria; Rimini, Emanuele ^[1]

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1. CNR-IMM, Stradale Primosole 50, 95121 Catania (Italy)

We experimentally investigate the isothermal amorphous-to-fcc polycrystalline phase transition process in amorphous Ge{sub 2}Sb{sub 2}Te{sub 5} thin films prepared by sputtering. The amorphous layers were either as deposited or formed by Ar{sup +} ion implantation after crystallization at 300 deg. C. The kinetics of the amorphous-to-polycrystal transition are analyzed through electrical measurements, in which the Johnson-Mehl-Avrami-Kolmogorov theory is employed. The procedure to extract the kinetics of the phase transition from conductivity versus time data is carefully discussed and compared to data of cross-sectional transmission electron microscopy images versus anneal time. By following this proposed procedure, the nucleation and growth parameters, and the activation energies have been determined. Results indicate that the process of isothermal crystallization in Ge{sub 2}Sb{sub 2}Te{sub 5} takes place in two stages, in which the Avrami exponent changes in the range from 3 to 1. These results are understood in terms of modifications in the kinetics of the phase transition.

• OSTI ID: 21356111
• Journal Information: Journal of Applied Physics, Vol. 105, Issue 8; Other Information: DOI: 10.1063/1.3093915; (c) 2009 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTIVATION ENERGY
ANNEALING
ARGON IONS
CRYSTAL GROWTH
CRYSTALLIZATION
DATA ANALYSIS
ELECTRIC CONDUCTIVITY
FCC LATTICES
GERMANIUM COMPOUNDS
ION IMPLANTATION
NUCLEATION
POLYCRYSTALS
SEMICONDUCTOR MATERIALS
SPUTTERING
SURFACE COATING
TELLURIUM COMPOUNDS
THIN FILMS
TIN COMPOUNDS
TRANSMISSION ELECTRON MICROSCOPY
CHARGED PARTICLES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTALS
CUBIC LATTICES
DEPOSITION
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
ENERGY
FILMS
HEAT TREATMENTS
IONS
MATERIALS
MICROSCOPY
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES