Coercivity of Neodymium magnets, could it be demagnetized in an MRI?

In summary, an N45 Grade Neodymium Rare Earth magnet has a remnance (Br) of 1320 mT and Coercive force (Hcj) of 923 kA/m. The units of A/m for Coercive Force can be converted to Gauss/Tesla using the relationship B=μo H. Placing this magnet in a 2T MRI could potentially demagnetize it or change its properties, as the H value of the MRI is higher than the coercive field of the magnet. However, it is not recommended to put strong magnets in an MRI.
  • #1
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An N45 Grade Neodymium Rare Earth magnet has a remnance (Br) of 1320 mT and Coercive force (Hcj) of 923 kA/m.

I am a little confused with the units of Coercive Force, how does A/m relate to Gauss/Tesla?

Also, if an N45 magnet was placed inside a 2T MRI, would that be strong enough to demagnetize it or change its magnetic properties?

Thank you.
 
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  • #2
Corresponds to ##\mu_r \approx 1140##

Putting strong magnets in an MRI looks like a bad idea, but I don't know how that would influence the magnet.
 
  • #3
The relationship between B and H in air is B=μo H.
The 2T correspond to a value of H higher that the coercive field of the magnet so it looks like it can be demagnetized by this field, if the field is in the right direction.
 

1. What is coercivity and how does it relate to neodymium magnets?

Coercivity is a measure of a material's resistance to being demagnetized. In the case of neodymium magnets, it refers to the amount of magnetic field required to reverse the magnetization of the magnet.

2. Can neodymium magnets be demagnetized in an MRI?

Yes, neodymium magnets can be demagnetized in an MRI due to the strong magnetic fields generated by the machine. This is because the magnetic field of the MRI can overcome the coercivity of the magnet, causing it to lose its magnetization.

3. Is there a risk of damaging the MRI machine if a neodymium magnet is brought into the room?

Yes, there is a risk of damaging the MRI machine if a neodymium magnet is brought into the room. The strong magnetic fields of the magnet can interfere with the operation of the MRI, potentially causing malfunctions or damage.

4. How can I safely use neodymium magnets in an environment with an MRI machine?

To safely use neodymium magnets in an environment with an MRI machine, it is important to keep the magnets at a safe distance from the machine. Additionally, it is recommended to use non-magnetic materials for any equipment or devices that will be used near the MRI.

5. Can the demagnetization of neodymium magnets in an MRI be reversed?

Yes, the demagnetization of neodymium magnets in an MRI can be reversed. This can be done by exposing the magnet to a strong magnetic field in the opposite direction, which can realign the magnetic domains and restore the magnet's magnetization.

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