Evidence of SnSb2Te4 rocksalt metastable phase of thin films grown by pulsed laser deposition

BILOVOL, V.; J. A. ROCCA; FONTANA, M.; M. A. UREÑA

Chisinau

Congreso; 9th International Conference on Amorphous and Nanostructured Chalcogenides; 2019

International Conference on Amorphous and Nanostructured Chalcogenides

SnSb2Te4,an intermetallic compounds in the pseudobinary SnTe-Sb2Te3,looks as a promising candidate forphase-change material in non-volatile memories applications. Thinfilms having thickness from 50 to 150 nm were grown by pulsed laserdeposition using SnSb2Te4as structure of 21 R-typestructure (R-3m)consisting of rocksalt-type blocks separated by van der Waals gap.While in thermal equilibrium this phase crystallizes into a complexcubic close-packed structure [1], the thin films obtained had asimple NaCl-structure (Fm-3m)(metastable phase) as it was deduced from conventional XRDmeasurements in grazing incidence of the investigated films. Themetastable phase transitioned to the stable complex structure duringthe measurements of electrical resistance on temperature dependence.119mSnconversion electron Mössbauer spectroscopy was used to investigatethe local environment of Sn atoms in as made film. The existence ofSn(II) in a high symmetry site was found as expected for SnSb2Te4.Nevertheless, the dominant contribution was Sn(IV) attributed to SnO2phase, evidencing an oxidation of the films surface. Theevidence of the metastable NaCl-structure of GeSb2Te4films induced by heating the amorphous film by laser irradiationwere reported [2-4]. Nevertheless, reports about SnSb2Te4film to date were not found.p { margin-bottom: 0.25cm; direction: ltr; line-height: 115%; text-align: left; orphans: 2; widows: 2; background: transparent }