Good thermal conductor but insulator

Click For Summary

Discussion Overview

The discussion centers on the search for a material that exhibits both good thermal conductivity and insulating properties at approximately 4 K, while also being relatively easy to fabricate. Participants explore various materials and their suitability for this specific application.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant inquires about materials that are good thermal conductors and insulators at low temperatures, specifically around 4 K.
  • Another participant suggests diamond as a potential candidate but notes that its fabrication is not easy.
  • Beryllium oxide (BeO) ceramic is mentioned as a possibility, with a caution about the need for careful processing due to toxicity concerns.
  • Thermally conductive ceramics and plastics are recommended as alternatives, with a suggestion to contact a specific company for more information.
  • Hard anodized aluminum is proposed as a solution, with the caveat that the anodized layer must remain intact to prevent electrical conduction.
  • A later reply indicates that hard anodized aluminum may not meet the requirements due to the need for the bulk material to be an insulator in the presence of AC magnetic fields.
  • Boron nitride is suggested as another material to consider for the application.

Areas of Agreement / Disagreement

Participants present multiple competing views on suitable materials, and the discussion remains unresolved regarding the best option that meets all specified criteria.

Contextual Notes

Participants express concerns about the fabrication difficulty and safety of certain materials, as well as the specific requirements for use at low temperatures and in AC magnetic fields.

Who May Find This Useful

Individuals interested in materials science, low-temperature physics, or engineering applications involving thermal management and electrical insulation may find this discussion relevant.

csopi
Messages
81
Reaction score
2
Hi,

Does anybody know a material which is a good thermal conductor and an insulator at the same time (at temperatures around 4 K) and is "easy" to fabricate? For e.g. sapphire fulfils the first two requirements, but is extrmely hard.
 
Engineering news on Phys.org
First through was diamond, but 'easy' to fabricate rules that out. Second thought is BeO ceramic, but must be processed very carefully to prevent Be poisoning. You may want to research thermally conductive ceramics - there may be some that are not dangerous to process. There are some thermally conductive plastics, best to contact www.coolpolymers.com
 
Thank you very much for your help, I'll look into the hints!
 
You might also consider simple hard anodized aluminum. The anodized layers should give you a thick enough oxide to prevent any electrical conduction. Of course, anything contacting it should not be able to break through this oxide layer.
 
Good idea, but unfortunatelly this won't solve my problem. I'll use it as a sample holder at 4 K, and it'll be subjected to AC magnetic fields. The aim is to get rid of the eddy currents and for this I need the bulk to be an insulator as well.
 
Have you considered Boron Nitride?
 

Similar threads

Replies
6
Views
2K
Replies
4
Views
2K
  • · Replies 10 ·
Replies
10
Views
4K
  • · Replies 27 ·
Replies
27
Views
6K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 6 ·
Replies
6
Views
1K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
8K