We synthesized glasses via melt and quench technique. We observed that high wavenumber (particularly >1000 cm^-1) region of the spectra consist of regularly increasing intensity curve with no visible band. I searched the literature, and found many published spectra such as ours. But, unfortunately, I could not find any explanation to the same. Can someone suggest me some book or paper to resolve the problem? If someone knows the reason, kindly share and help me out.
Generally, such phenomenon mean you have luminescence. Try to change excitation wavelength or take PL spectra and choose correct region for measurement.
If the intensity is increasing with each measurement, you're probably got thermal background, try to reduce laser power.
Prof. Krylov, thank you for your kind advice. I will study literature to understand luminescence observed in Raman spectra of the glasses. Also I will try the experimental alternatives suggested by you...
Thanks Dr. Bratashov for your kind atention and suggestions. I will try eliminate thermal background by reducing laser power as per your suggestion..
Thanks Sanz Sir for your kind reply. We have XRD graphs of the samples. Actually, we have two types of samples 1. glass (amorphous, no XRD peaks) and 2. glass ceramics (partially crystalline). But regardless the XRD patterns, Raman spectra of each sample is having a continuously raising curve at higher wavenumers as explained in the question above.
Hi Satwinder, you could try using a different excitation wavelength: excitation at 785 nm results in luminescence in glass, as Alexander pointed out. I think it's due to the presence of alkali metal ions in the borosilicate glasses. I've found that with 488 nm excitation this doesn't happen.
Respected Dr. Michel, my hearty thanks to you for your kind response. I will try to have spectra again with your recommended wavelength Mam.
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Physical Phenomena
- Luminescence
- Fluorescence