Abstract

A new polar quaternary chalcogenide, Na8Mn2(Ge2Se6)2, has been synthesized using the building-block approach by reacting preformed Na6Ge2Se6 and MnCl2 at 750 °C. The structure consists of layers of [Na(1)Mn(Ge2Se6)]3– stacked perpendicular to the c-axis and sodium ions occupying the interlayer space. An indirect bandgap of 1.52 eV has been calculated using density functional theory, which is expectedly underestimated compared to the observed optical bandgap of 1.95 eV derived from diffuse reflectance spectroscopic measurements in the UV/Vis/NIR region. Magnetic measurements confirm the paramagnetic nature of Na8Mn2(Ge2Se6)2 with an experimental magnetic moment of 5.8 μB in good agreement with the theoretical spin only moment of 5.92 μB for high spin Mn2+. Na8Mn2(Ge2Se6)2 exhibits a potentially wide region of transparency in the measured range of 2.5–25 µm. Na8Mn2(Ge2Se6)2 shows a modest second-harmonic generation (SHG) response but with a high laser-induced damage threshold (LIDT) of ~9x AgGaSe2. Third harmonic generation (THG) measurements indicate that Na8Mn2(Ge2Se6)2 displays a high THG coefficient (1.9x AgGaSe2) at λ = 1800 nm.

Department(s)

Physics

Second Department

Chemistry

Comments

National Science Foundation, Grant DMR- 1809128

Keywords and Phrases

Chalcogenides; High LIDT; NLO; Polar crystal; SHG; THG

International Standard Serial Number (ISSN)

0925-8388

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2023 Elsevier, All rights reserved.

Publication Date

15 Apr 2022

Share

 
COinS