I am dealing with an alloy of TbFe. We found the magnetic coercivity of about 4 T at 2 K. The Curie temperature was recorded at about 200 K. All these properties are observed at very low temperatures. Can anyone help and suggest possible applications for such material.
The coercivity is really high. What is the particle size of the material? Usually, for high density magnetic recording related applications, magnetic nanoparticles with high magnetocrystalline anisotropy are required.
Amit, thank you very much for your help. In this case, the particle sizes are in the range of 10-15 nm. The material is an amorphous state.
Can it be used as a high-density magnetic recording although it has low Curie temperature (200 K) and high coercivity is at 2K (both are below room temperature)?
Yes I didn't notice that it was observed at 2K. For high density magnetic recording, it is of course preferable to have high magnetocrystalline anisotropy near Room temperature. However, there is another possibility. Your material could be useful for Cryogenic permanent magnet undulator.
Hi Shiv,
What is the saturation magnetization and remanence values at that temperature?
Hi Rajasekhar,
It was not completely saturated until 7 T. The remanence value is 120 A.m2/kg.
Thanks!
Hi Shiv,
The remanence value is reasonable. Here is an article (Article Nd2Fe14B and Pr2Fe14B magnets characterisation and modelling...
) that compares the low temperature magnetic properties of magnets based on Pr2Fe14B and Nd2Fe14B. The Pr2Fe14B magnets are suitable for low temperature (< 77 K) applications mentioned by Amit. You may compare your properties with these magnets. There is another article https://www.nature.com/articles/nmat4248 you may want to see.Raj
First make it clear, is it normal coercivity or intrinsic coercivity? Intrinsic coercivity of 4 T cannot be considered very high at 2 K because the anisotropy field of Tb is very high at 2 K.
What is the coercivity of your alloy at 190 K? If the coercivity is decreasing swiftly, than the alloys is not very useful. If the coercivity is not decreasing swiftly then you can try to increase its ordering temperature by adding interstitial elements such as C, B (If they work!!!!) or by substituting Fe by Co/Ni.
The inter-atomic distance (Fe-Fe) seems very narrow in your alloy, so the ordering temperature is very low.
Sajjad Ur Rehman Thanks for the answer. I did not measure the coercivity at 190 K. But at the room temperature (300 K), the coercivity was very low (about zero).