Ferromagnetic-Paramagnetic Transition near Room Temperature

[Jsanchezp]

Hello everyone,I would like to open a debate on the possibility of designing permanent magnets whose Curie temperature (Tc) is as close as possible to room temperature, without compromising the intensity of the magnetic field. The goal is to find an optimal balance between a ‘low’ Tc and maintaining powerful magnetic properties.

Is there a viable research window in this sense? Could alloys and/or new manufacturing processes be used to precisely adjust the Tc? I am particularly interested in the following aspects

* Synthesis of materials capable of maintaining a high magnetic moment at a Tc close to room temperature.

* Structural modifications (doping, thermal or mechanical treatments) that control the ferromagnetic-paramagnetic transition.

* Recent or emerging lines of research into alloys with unconventional elements and advanced characterisation methods (e.g. neutron spectroscopy, high-resolution microscopy, etc.).

* Potential applications in which this property could have a major impact (sensors, actuators, biomedical devices, etc.).

I would particularly appreciate the opinion of those working in the engineering of magnetic materials, characterisation and design of advanced magnets. Where would you advise starting? What limitations or challenges do you see in the short and medium term? Thank you for sharing your experience!

 

[berkeman]

Welcome to PF.

Interesting question. What have you found so far in your searching on the subject? What have you found so far about things that affect the Curie temperature of different materials?

https://en.wikipedia.org/wiki/Curie_temperature

From that article, it looks like there is one material that has a $T_c$ of 20.1C (there you go!) and one at 45C. What is special about those materials?

<<snip>>

 

[Astronuc]

Recent or emerging lines of research into alloys with unconventional elements

One will wish to read
J.M.D.Coey, Perspective and Prospects for Rare Earth Permanent Magnets
Engineering 6 (2020) 119–131
https://doi.org/10.1016/j.eng.2018.11.034
Rare Earth Permanent Magnets—Review

possibility of designing permanent magnets whose Curie temperature (Tc) is as close as possible to room temperature,

Why?

Potential applications in which this property could have a major impact (sensors, actuators, biomedical devices, etc.).

There are many.

Edit/update:

Terbium's magnetic properties have led to its use in the production of powerful magnets. These magnets find applications in various electronic devices, including hard disk drives and electric motors. The use of terbium in magnets enhances the overall performance and efficiency of these devices, making them more compact and powerful.

Ref: https://www.stanfordmaterials.com/blog/terbium-uses-in-electronics.html