DOS for impurities in a dielectric

In summary, ferromagnetic impurities can lead to an unstable dielectric material. The f-levels of the ions barely respond to the dielectric, so crystal field theory may be a good way to calculate the splitting.
  • #1
f95toli
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I have a question regarind how to calculate the DOS for ferromagnetic impurities in a dielectric

We have samples with ferromagnetic rare-earth ions implanted in a dielectric material. The concentration known and is quite high but the ions are probably only interacting weakly (they are on average about 10nm apart).These ions can interact with an external field (which does not affect the dielectric).

I now need to calculate the DOS of the ions interacting with the field. However, I do not even know where to start (possibly because I haven't done anything like this in >15 years).

I believe the interactions are a bit too weak for it to be considered a spin glass. However, the usual theory for disordered glasses should apply.

Any ideas for where to start? Presumably it should be calculable since I know the concentration and the properties of the ions (and they are not interacting)
 
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  • #2
I am a little bit confused: If the ions are non-interacting, how can they be ferromagnetic? I suppose you mean paramagnetic at best.
The f-levels of the ions should hardly be influenced by the dielectric. I would look out for crystal field theory to calculate the splitting.
If you know some German, the book "Einführung in die Festkörperphysik" by K.-H. Hellwege may prove useful as it contains lots of stuff on lanthanide magnetism.
 
  • #3
Sorry, I wasn't thinking when I wrote that:shy:
What I meant was that the ions come from a rare-earth metal which is ferromagnetic; but if the ions in the dielectric are dilute enough there shouldn't be any magnetic ordering(although we are not quite sure)

My German is rusty (to say the least) but I will see if I can find that book.
 
  • #4
There should be plenty of stuff around.
E.g., salts like Gadolinium sulphate octahydrate have been used extensively in adiabatic demagnetization.
Even in these salts, collective effects are often weak.
Oldies but goldies:
http://www.dtic.mil/dtic/tr/fulltext/u2/a122791.pdf
 
  • #5
Thanks
That reference looks very useful, I will try to read it this week (once I've finished about two days worth of non-physics-related paperwork)
 

1. What is DOS for impurities in a dielectric?

DOS stands for Density of States. In the context of impurities in a dielectric, it refers to the number of energy states that are available for the impurity atoms to occupy. It is an important parameter that affects the electrical and optical properties of the dielectric material.

2. Why is DOS important for impurities in a dielectric?

DOS plays a crucial role in determining the electronic and optical properties of a dielectric material. It affects the charge transport, recombination rates, and optical absorption of the material. Therefore, understanding the DOS for impurities in a dielectric is essential for designing and optimizing electronic devices.

3. How is DOS for impurities in a dielectric calculated?

DOS can be calculated using theoretical models, such as density functional theory (DFT) or tight-binding approximation, or experimentally through techniques like photoemission spectroscopy. These methods take into account the electronic structure and energy levels of the impurity atoms in the dielectric material.

4. What factors can affect the DOS for impurities in a dielectric?

The DOS for impurities in a dielectric can be influenced by several factors, including the type and concentration of impurities, the crystal structure of the dielectric material, and the surrounding environment. The presence of defects or other impurities can also affect the DOS.

5. How can the DOS for impurities in a dielectric be controlled?

The DOS for impurities in a dielectric can be controlled by carefully choosing the type and concentration of impurities and by modifying the crystal structure of the dielectric material. Additionally, the use of surface treatments or doping techniques can also help in controlling the DOS and improving the desired properties of the material.

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