Variations in Electric Switching and Transverse Resistance of GeTe/ Sb2Te3 Superlattices at Elevated Temperature Studied by Conductive Scanning Probe Microscopy

Temperature-dependent variations in electric switching and transverse resistance of phase-change [(GeTe) 2 (Sb 2 Te 3 )] n (n=4 and 8) chalcogenide superlattice (CSL) films were studied using conductive scanning probe microscopy (SPM). Three temperature regions with different electric transport prop...

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Bibliographic Details
Published in:MRS advances Vol. 3; no. 5; pp. 241 - 246
Main Authors: Bolotov, Leonid, Saito, Yuta, Tada, Tetsuya, Tominaga, Junji
Format: Journal Article
Language:English
Published: New York, USA Materials Research Society 2018
Springer International Publishing
Subjects:
Applied and Technical Physics
Biomaterials
Characterization and Evaluation of Materials
Materials Engineering
Materials Science
Nanotechnology
electrical properties
scanning probe microscopy (SPM)
phase transformation
ISSN:2059-8521, 2059-8521
Online Access:Get full text
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Summary:Temperature-dependent variations in electric switching and transverse resistance of phase-change [(GeTe) 2 (Sb 2 Te 3 )] n (n=4 and 8) chalcogenide superlattice (CSL) films were studied using conductive scanning probe microscopy (SPM). Three temperature regions with different electric transport properties were recognized in point current-voltage (I-V) spectra and the surface potential maps measured with tantalum and platinum-coated SPM cantilevers. At around 80°C the switching voltage decreased abruptly from ∼2 V to 0.5 V and the thermal coefficient of resistance changes its sign, indicating different carrier transport mechanisms. The observed changes correlated with decrease in the surface potential by ∼150 meV from 25 to 150°C. The results were ascribed to an opening of the CSL electronic band gap near the Fermi energy caused by thermal stress, which led to the transition from a Dirac-like semimetal to a narrow-gap semiconductor.
ISSN:2059-8521
2059-8521
DOI:10.1557/adv.2018.241