Related Experiment Video
Updated: Apr 2, 2026

A Novel Technique for Raman Analysis of Highly Radioactive Samples Using Any Standard Micro-Raman Spectrometer
Published on: April 12, 2017
Vibrational and electronic properties of Np[Formula: see text]O[Formula: see text] from experimental spectroscopy and
Binod K Rai1, Shuxiang Zhou2, Benjamin R Heiner3
1Savannah River National Laboratory, Aiken, SC, 29808, USA. binod.rai@srnl.doe.gov.
Abstract:
High-valence actinide oxides are critical to understanding the behavior of 5f-electrons, yet their structural and electronic properties remain poorly understood due to challenges in synthesis and handling. We report the first Raman spectroscopic study of single-crystalline Np[Formula: see text]O[Formula: see text] and the first scanning tunneling spectroscopy (STS) measurement on any neptunium-containing material. Hydrothermally synthesized crystals were structurally verified by X-ray diffraction. Raman spectra revealed sharply resolved vibrational features, including previously unreported low-frequency modes. STS measurements revealed a band gap of 1.5 eV. Density functional theory (DFT) enables vibrational mode assignments, reveals neptunium-dominated low-frequency phonons, oxygen-dominated high-frequency modes, and predicts an indirect band gap of 1.68 eV. This predicted value is in excellent agreement with the experimentally measured STS gap. This combined Raman, DFT, and STS approach provides a robust framework for correlating lattice dynamics and electronic structure in actinide materials, providing benchmark data for Np[Formula: see text]O[Formula: see text], and opening new avenues for probing structure-property relationships in complex f-electron materials.
Related Concept Videos
π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds
Molecular Orbital Theory II
UV–Vis Spectroscopy: Molecular Electronic Transitions
π Electron Effects on Chemical Shift: Overview
Molecular Orbital Theory I
Other Nuclides: 31P, 19F, 15N NMR
While fluorine-19 and phosphorous-31 have high natural abundances (100%) and positive gyromagnetic ratios, nitrogen-15 has a low natural abundance and a negative gyromagnetic ratio. However, nitrogen-15 is still preferred over nitrogen-14 (which has a...

