There are no materials that can completely block a magnetic field. However, there are materials that can significantly reduce the magnetic field in a specific area, known as magnetic shields.
The most commonly used material for magnetic field shielding is iron, which has very high magnetic permeability. Other materials such as stainless steel, cobalt, nickel, and copper can also be used for magnetic field shielding, but their effectiveness is usually lower compared to iron.
Shielding involves placing a material with high magnetic permeability between the source of the magnetic field and the area we want to protect. This material forms a Faraday cage, which attracts the lines of magnetic force and reduces their impact on the protected area.
In summary, there are no materials that can completely block a magnetic field, but iron and other materials with high magnetic permeability can be used for magnetic field shielding to reduce its influence on a specific area.