X-ray diffraction in the presence of electric potential

[bearcharge]

Hi, I was conducting an experiment on a material using XRD and I investigated two cases. One case is the presence of outside electric potential, that is, the material being connected to a electric circuit. The other case is the absence of this electric potential. I found that the two XRD patterns from these two cases differ, though not significantly. I think this is suggesting that the exerted electric potential is changing the original electron distribution, which is not surprising, right? Considering that the sample contains Ti⁴⁺ which has empty 3d orbitals, does this fact possibly has relationship to what I observed? Yes, I think I'm implying the interaction of X-ray with possible light-sensitive material in the presence of an electric potential. I'm sorry if this question belongs more to the chemistry area :) Thanks!

 

[JeffKoch]

What sort of external fields are we talking about here? I'm not familiar with such an effect, which doesn't mean it isn't commonly known to others, but I would expect it if the fields are large enough to perturb molecular wavefunctions and therefore interatomic bonds. You see analogous effects with isolated atoms, Stark line broadening and shifts.

 

[fleem]

A piezoelectric effect could also cause this, but it'd have to be a big effect, I think.

 

[bearcharge]

What sort of external fields are we talking about here? I'm not familiar with such an effect, which doesn't mean it isn't commonly known to others, but I would expect it if the fields are large enough to perturb molecular wavefunctions and therefore interatomic bonds. You see analogous effects with isolated atoms, Stark line broadening and shifts.

Thanks for the answer. Actually, I was talking about an in situ synchrotron XRD of a battery material during discharging. During discharging, a two-phase transition was expected. However, this was not observed when the discharging was going on. Instead, the phase changed can be observed when I stopped the discharging circuit and then radiated the X-ray beam. I wonder if external electric potential is playing a role in this even though this potential is as small as several Vs...

 

[bearcharge]

A piezoelectric effect could also cause this, but it'd have to be a big effect, I think.

Thank you for the suggestion! As I explained in the previous reply, the external potential is only several Vs. I assume this is far from being big... The experiment result is peculiar as it didn't happen for other materials but for this one which has a Ti4+ in it. I was wondering if this is something special...