Typical Raman Peaks for LaWN₃

• 600–950 cm⁻¹: W–N stretching vibrations.
• 400–600 cm⁻¹: Mixed W–N and W–O bending vibrations.
• 150–400 cm⁻¹: Octahedral tilting, lattice vibrations, and La translational modes.
• Below 150 cm⁻¹: Lattice phonons or structural distortions induced by nitrogen incorporation.

For nitrogen-incorporated tungstates:

• W–N bonds shift stretching frequencies higher (relative to W–O bonds in La₂WO₆).
• Broadening or splitting of peaks may occur due to nitrogen disorder and reduced symmetry.

Nitrogen primarily replaces oxygen in the W(O,N)₆ octahedra, forming stronger W–N bonds.

Nitrogen substitution introduces asymmetry, increasing Raman activity in previously silent or weak modes.

W–N bonds have higher vibrational frequencies than W–O.

Raman peaks for W–N are sharper and distinct due to stronger bonds.