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Unique Bond Breaking in Crystalline Phase Change Materials and the Quest for Metavalent Bonding
Author(s) -
Zhu Min,
CojocaruMirédin Oana,
Mio Antonio M.,
Keutgen Jens,
Küpers Michael,
Yu Yuan,
Cho JuYoung,
Dronskowski Richard,
Wuttig Matthias
Publication year - 2018
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201706735
Subject(s) - amorphous solid , materials science , evaporation , phase (matter) , chemical physics , covalent bond , ionic bonding , phase change , structural change , bonding in solids , chemical bond , atom probe , crystallography , nanotechnology , ion , composite material , thermodynamics , chemistry , organic chemistry , physics , macroeconomics , economics , transmission electron microscopy
Laser‐assisted field evaporation is studied in a large number of compounds, including amorphous and crystalline phase change materials employing atom probe tomography. This study reveals significant differences in field evaporation between amorphous and crystalline phase change materials. High probabilities for multiple events with more than a single ion detected per laser pulse are only found for crystalline phase change materials. The specifics of this unusual field evaporation are unlike any other mechanism shown previously to lead to high probabilities of multiple events. On the contrary, amorphous phase change materials as well as other covalently bonded compounds and metals possess much lower probabilities for multiple events. Hence, laser‐assisted field evaporation in amorphous and crystalline phase change materials reveals striking differences in bond rupture. This is indicative for pronounced differences in bonding. These findings imply that the bonding mechanism in crystalline phase change materials differs substantially from conventional bonding mechanisms such as metallic, ionic, and covalent bonding. Instead, the data reported here confirm a recently developed conjecture, namely that metavalent bonding is a novel bonding mechanism besides those mentioned previously.