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Menezes LT, Assoud A, Kleinke H. Crystal structure, phase width, and physical properties of the barium tetrel selenides Ba 6Si 2-xGe xSe 12 ( x = 0, 0.5, 1, and 1.5) with ultralow thermal conductivity. Dalton Trans 2023; 52:15831-15838. [PMID: 37819244 DOI: 10.1039/d3dt02516k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
The new compound Ba6Si2Se12 was synthesized, and the crystal structure and physical properties are reported here. Ba6Si2Se12 adopts a new structure type in the triclinic P1̄ space group with the lattice parameters a = 9.1822(7) Å, b = 12.2633(14) Å, c = 12.3636(18) Å, α = 109.277(3)°, β = 104.734(2)°, and γ = 100.4067(16)°. Notably, the structure features disordered Se22- dumbbells that have also been observed in the germanium selenide with the analogous stoichiometry (Ba6Ge2Se12). Density functional theory calculations revealed that Ba6Si2Se12 is a semiconductor with a calculated band gap of 1.74 eV. UV/vis/NIR absorption spectra indicated that the experimental band gap of Ba6Si2Se12 is 1.89 eV. While exploring this compound's phase width, it was discovered that up to 75% of the Si could be substituted with Ge while retaining the structure type. Rietveld refinements were performed on the phase-pure samples of Ba6Si2-xGexSe12 (x = 0, 0.5, 1, and 1.5) using data collected at the Canadian Light Source's High Energy Wiggler Beamline. The cell parameters, Si/Ge occupancies, and disordered Se22- occupancies were studied. Raman spectra displayed the expected Si-Se and Ge-Se stretching modes from 215 cm-1 to 280 cm-1. The samples were also hot-pressed into pellets to determine their thermal conductivity values ranging from 0.5 to 0.4 W m-1 K-1 for the x = 0, 0.5, and 1.5 samples. The x = 1 sample stood out with a remarkably low thermal conductivity of 0.3 W m-1 K-1, consistent from room temperature up to 573 K.
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Affiliation(s)
- Luke T Menezes
- Department of Chemistry and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
| | - Abdeljalil Assoud
- Department of Chemistry and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
| | - Holger Kleinke
- Department of Chemistry and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
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Xie W, Yun Y, Deng L, Li G, Pan S. Second-Harmonic Generation-Positive Na 2Ga 2SiS 6 with a Broad Band Gap and a High Laser Damage Threshold. Inorg Chem 2022; 61:7546-7552. [PMID: 35511479 DOI: 10.1021/acs.inorgchem.2c00676] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The development of high-power solid-state lasers is in urgent need of new infrared nonlinear optical (IR NLO) materials with a wide band gap and a high laser-induced damage threshold. A new infrared nonlinear optical material Na2Ga2SiS6 has been synthesized for the first time, crystallizing in the Fdd2 (no. 43) noncentrosymmetric space group. Its three-dimensional tunnel framework consists of two typical NLO active motifs [GaS4] and [SiS4], with Na+ cations located inside the tunnels. Na2Ga2SiS6 exhibits comprehensive optical properties, namely, a wide transmission range, a high laser-induced damage threshold (10 × AgGaS2), a type-I phase-matching second-harmonic generation response (0.2 × AgGaS2), and especially a wide band gap (3.93 eV), which is the largest in the A2MIII2MIVQ6 (A = alkali metals; MIII = IIIA elements; MIV = IVA elements; Q = S and Se) family. Therefore, Na2Ga2SiS6 does not produce two-photon absorption under a 1064 nm laser pump and could be used in high-energy laser systems, which makes Na2Ga2SiS6 a promising candidate for high-energy IR NLO applications.
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Affiliation(s)
- Wenlong Xie
- CAS Key Laboratory of Functional Materials and Devices for Special Environments, Xinjiang Technical Institute of Physics & Chemistry, CAS, and Xinjiang Key Laboratory of Electronic Information Materials and Devices, 40-1 South Beijing Road, Urumqi 830011, China
| | - Yihan Yun
- CAS Key Laboratory of Functional Materials and Devices for Special Environments, Xinjiang Technical Institute of Physics & Chemistry, CAS, and Xinjiang Key Laboratory of Electronic Information Materials and Devices, 40-1 South Beijing Road, Urumqi 830011, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lihan Deng
- CAS Key Laboratory of Functional Materials and Devices for Special Environments, Xinjiang Technical Institute of Physics & Chemistry, CAS, and Xinjiang Key Laboratory of Electronic Information Materials and Devices, 40-1 South Beijing Road, Urumqi 830011, China
| | - Guangmao Li
- CAS Key Laboratory of Functional Materials and Devices for Special Environments, Xinjiang Technical Institute of Physics & Chemistry, CAS, and Xinjiang Key Laboratory of Electronic Information Materials and Devices, 40-1 South Beijing Road, Urumqi 830011, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shilie Pan
- CAS Key Laboratory of Functional Materials and Devices for Special Environments, Xinjiang Technical Institute of Physics & Chemistry, CAS, and Xinjiang Key Laboratory of Electronic Information Materials and Devices, 40-1 South Beijing Road, Urumqi 830011, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
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