The simple answer is that it is not possible to totally 'block' a magnetic field. The essence of a magnet, as determined by nature, is that magnetic field lines must terminate on the opposite pole and, therefore, there is no way to stop them.
Materials for Magnetic Shielding
The best material for magnetic shielding is any ferromagnetic metal. This includes materials that contain iron, nickel, or cobalt.
There are some specialised materials designed and made for magnetic shielding. The most common of these specialised materials is MuMetal or some other proprietary alloys. Most of these will have a high nickel content, with either 50% or 80% nickel content.
Answer and Explanation: The environmental factors that can affect a magnet's force are sheer force, heat, temperature, air gaps, metal thickness, material and corrosion.
The magnitude of the magnetic force between them depends on how much charge is in how much motion in each of the two objects and how far apart they are. The direction of the force depends on the relative directions of motion of the charge in each case.
The short answer is no, there is no shield or substance that will effectively block magnetic fields as such.
At frequencies from 30 to 100 MHz, aluminum foil provides at least 85 dB of shielding effectiveness. Unfortunately, aluminum foil is extremely inadequate against low frequency magnetic fields, where thick steel or highly permeable ferrite material provides more adequate shielding.
For low field strength, sensitive electronics, MuMetal can provide better shielding than steel. For many applications involving large, powerful neodymium magnets, the higher saturation point of steel serves better. In many specific cases we're asked about, a steel sheet-metal shield is often the best solution.
Temperature can either strengthen or weaken a magnet's attractive forces. Cooling or exposing the magnet to low temperatures will enhance and strengthen the magnetic properties, while heating will weaken them.
Many common metals such as aluminum, copper, brass, gold, silver, titanium, tungsten, and lead are not ferromagnetic. They cannot be made into magnets and will not be attracted to magnetic fields.
All metals that act as good shields are also attractive to magnets. If you're using a stainless steel like 316 that isn't ferromagnetic, it's not blocking any fields, at least not any more than an air gap.
For one, the paper is non-magnetic and thin, so it doesn't do an effective job of blocking the magnetic attraction. The magnets stick to the sheet of metal, because it is a magnetic object. However, ferromagnetic materials are used in order to shield, or redirect, magnetic fields.
Shielding from Electromagnetic Interference and External Magnetic Fields. Protect Sensitive Electronic Equipment or Appliances. High and Low Permeability Options Available.
Magnetism is very important in various areas of science and technology, ranging from magnetic recording through energy generation to trapping cold atoms. Physicists have managed to master magnetism—to create and manipulate magnetic fields—almost at will.
Several factors can weaken the magnetism in a magnet. If a magnet is stored close to heat, strong electrical currents, other magnets, or radiation, it can lose its strength. Additionally, high humidity can corrode neodymium magnets.
Exposure to water can affect the performance and pull of a magnet. If the plating on a magnet becomes damaged, the magnet can become exposed to water. This exposure to water can cause the magnet to rust, resulting in a deterioration in the magnetic performance.
A: It wouldn't make much difference because water has very little magnetism whether hot or cold. If the water were hot enough, however, it could cause the "permanent" magnets themselves to weaken. That's because when heated the magnetic domains can rearrange, and they tend to cancel each other out.
The factors affecting the strength of a magnetic field at a point due to a straight current-carrying conductor are the magnitude of the electric current and the perpendicular distance between the point and the conductor.
Some magnets are more susceptible to corrosion and oxidation, such as neodymium iron boron magnets. If the humidity around the magnet is high, and the surface of the magnet is not treated with anti-corrosion or anti-oxidation, the performance and service life of the magnet will be affected.
If you attach a magnet to a very thin plate, the steel may become magnetically saturated. This means that it can't hold all the the magnet's flux, and you don't get 100% of the pull force you would with a thicker plate.
Some stainless steels are magnetic, and others are not. The defining factor of magnetism comes down to the the steel's microstructure. Martensitic stainless steels (which have a ferritic microstructure) are magnetic. Austenitic stainless steels contain nickel and are non-magnetic.
Certain metals in their natural states such as aluminium, copper, brass, lead gold, and silver don't attract magnets due to the fact they are weak metals. However, properties including iron and steel can be added to these metals in order to make them magnetic.