Vacancy ordering induced topological electronic transition in bulk Eu₂ZnSb₂

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid-State Chemistry

Background:

• Metal-semiconductor transitions are observed in nanoribbons, particularly those with honeycomb lattices.
• Understanding these transitions in bulk complex materials is crucial for novel electronic applications.

Purpose of the Study:

• To generalize metal-semiconductor transitions observed in nanoribbons to bulk Zintl semiconductors.
• To investigate the role of vacancy ordering in Eu2ZnSb2 and its impact on electronic properties.
• To explore tunable and switchable topological electronic behavior in Zintl compounds.

Main Methods:

• Theoretical modeling of five Eu2ZnSb2 structural models.
• Analysis of electronic band structures for different vacancy ordering configurations.
• Correlation of structural changes with electronic properties, including bandgaps and metallicity.

Main Results:

• Zigzag vacancy ordering in Eu2ZnSb2 leads to metallicity.
• Armchair vacancy ordering results in semiconducting behavior with indirect bandgaps.
• Bandgap size in armchair models correlates with inter-chain distances.
• Topological electronic structure changes are linked to cation ordering, suggesting tunable behavior.

Conclusions:

• Vacancy ordering is a key factor in metal-semiconductor transitions in Zintl compounds.
• Eu2ZnSb2 exhibits tunable electronic properties based on structural configurations.
• The findings suggest potential for switchable topological electronic states in Zintl materials, relevant for thermoelectrics.