Dear Aurelio Sanz Arranz,

Thanks for your reply. I used 532 nm wavelength laser. However, it is strange that I did not observe these bands repeatedly. I repeated the measurements. One time I observed and one time didn't. However, I will investigate the things based on the information provided by you.

Thanks,

Regards,

Sarfraz

Muhammad Sarfraz Arshad, if you used a 532 nm Raman system (18700 cm-1 in energy). You can check in nm where your band is and can compare it with the Sm3+ emissions. The method is straightforward:

1) Convert the laser wavelength from nm to cm-1as follows (1/532)*10^(7). The result is going to be 18796 cm-1

2) The laser position is zero position for the Stokes and anti-Stoke Raman band position in Raman-shift. With that in mind, you have to subtract or sum your band positions (1260, 1315, and 1360 cm-1) to the laser line position (18796 cm-1) - depending on Stokes or Anti-Stokes lines used.

3) Your bands in energy will be between (17536 to 17436 cm-1). Subsequently, you have to convert that values (17536 to 17436 cm-1) to nm again, which is the inverse process of (1).

4) The values of your band positions will be between 570 to 574 nm. So, now, you can compare that with the Sm3+ emissions from the literature.

5) If you check the Diker Diagram of the Rare-earths, you will see that the bands may correspond to 4G5/2-->6H5/2 emission level located at ~570 nm (in ~18000 cm-1).

Hoping that the explanation can be useful for you. This is the practical method to check if the bands are Raman bands or Rare-earth emissions.

Best,

Emmanuel

Emmanuel Lalla Thank you very much for elaborating everything in detail. I will check it. I really learnt a new thing. Thank you for this.

Stay blessed.

Best Regards,

Sarfraz

Muhammad Sarfraz Arshad, you may check the compounds' purity because you can have fluorescence or Raman bands from the rest of the starting compounds when doing the synthesis. For example, if you used an organic component for the synthesis and the resulting samples are not purified properly, the bands you presented above could be organic (C-C Raman bands). Without more information, these are thoughts and guessing about it. Thanks.

@ Emmanuel Lalla, I have done Raman spectroscopy of my samples again using a different laser. But you were right, these bands were due to Sm+3 (Photoluminescence). I also considered the possibility of presence of starting materials or C-C Raman bands but the presence of Sm+3 photoluminescence was more convincing, in fact, confirmed by other laser as these bands were there even when I calcined my materials at high temperature.

Thanks for your suggestions.

Best Regards,

Sarfraz