研究目的
To clarify the electronic structures and electric properties of marcasite-type RuN2 and RhN2, arsenopyrite-type IrN2, and pyrite-type PtN2 using synchrotron radiation infrared spectroscopy and first-principles calculations.
研究成果
The IR reflectance spectra confirm the metallic nature of marcasite-type RuN2 and RhN2 and semiconducting properties of arsenopyrite-type IrN2 and pyrite-type PtN2, with estimated band gaps of 0.8 eV and 2.1 eV, respectively. The findings are consistent with first-principles calculations, though some discrepancies indicate areas for further study, such as inclusion of spin-orbit effects and investigation of additional excitations.
研究不足
The pernitride specimens are very small, synthesized under high pressure, which may limit the accuracy of measurements; spin-orbit interaction was neglected in calculations, which could affect results; discrepancies between measured and calculated spectra for RhN2 suggest unaccounted excitations; use of NaCl pressure medium might introduce uniaxial effects, though not observed.
1：Experimental Design and Method Selection:
Synchrotron radiation infrared spectroscopy was used to measure reflectance spectra, combined with first-principles calculations based on density functional theory (DFT) using the WIEN2k code with GGA-PBE and MBJ potentials.
2：Sample Selection and Data Sources:
Pernitride specimens of RuN2, RhN2, IrN2, and PtN2 were synthesized under high pressure and temperature in a laser-heated diamond anvil cell (LH-DAC) via direct reaction with supercritical nitrogen fluid.
3：List of Experimental Equipment and Materials:
Equipment includes beamline BL43IR at SPring-8, microscopes (BRUKER Hyperion 2000 or custom-made), FTIR spectrometers (BRUKER Vertex70 or IFS120HR), detectors (Si-bolometer or HgCdTe), diamond anvil cell (DAC), type IIa diamond anvils, pressure-transmitting media (nitrogen or NaCl), reference Au, ruby ball for pressure measurement.
4：Experimental Procedures and Operational Workflow:
Specimens were placed in DAC for IR reflectance measurements under various pressures; reflectance spectra were recorded between 0.01 and 1.9 eV photon energies, averaged over several points, and normalized to reference Au spectra; ambient pressure measurements were also conducted for recovered specimens.
5：01 and 9 eV photon energies, averaged over several points, and normalized to reference Au spectra; ambient pressure measurements were also conducted for recovered specimens. Data Analysis Methods:
5. Data Analysis Methods: Reflectance spectra were analyzed using Drude-Lorentz model fitting; optical constants and band gaps were calculated from DFT results using Kramers-Kronig relations and MBJ potential for improved accuracy.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
