Not all magnets are created equal. Magnets come in many shapes and forms. Magnets are used for hundreds of applications from large industry purposes like the automotive industry to domestic applications such as audio speakers; you will even find them in your television. With so many different types, shapes, and strengths of magnets it can be easy to mistake an industrial magnet for a healing magnet. I will discuss the difference between the various materials magnets can be made from and their applications.

Ferrite magnets

Hard ferrite (ceramic) magnets were developed in the 1960's as a low cost alternative to metallic magnets. They are made from strontium carbonate and iron oxide both of which are readily available and low in cost. Even though they exhibit low magnetic fields (compared with other permanent magnet materials),ferrite magnets are widely used for industrial and domestic purposes. Ferrite magnets have good resistance to demagnetization, excellent corrosion resistance and the biggest advantage of such economic cost.

Ferrite magnets are made in many shapes and sizes, cylinders, bars, discs, horse shoes and rings.

The positive benefits of ferrite magnets are

? They retain their magnetism for a very long time.

? They have a high stability and do not demagnetise very easily even in high temperatures.

? They are relatively low cost to produce.

? They can be manufactured to be flexible, by mixing the ferrite with plasticized rubber compounds, which creates a bendy and pliable magnet.

The main drawback of ferrite magnets is that they are quite fragile and tend to break easily, so they should be handled with care.

Ferrite magnets are used for healing purposes. They are commonly found in magnetic therapy wraps, straps, magnetic bedding and shoe insoles (using flexible ferrite magnets). Whilst ferrite magnets will keep their magnetism for a very long time you must always be careful to ensure that their strength is adequate. Each magnet should be at least 800 gauss. You should also be wary of products that could be easily damaged as once the magnets are broken the magnetic device should be discarded.

Neodymium magnets

Neodymium magnets are a member of the rare earth magnet family and are the most powerful permanent magnets in the world. They are also referred to as NdFeB magnets, or NIB, because they are composed mainly of Neodymium (Nd), Iron (Fe) and Boron (B). They are a relatively new invention, first manufactured in 1984 and have only recently become affordable for everyday use.

Neodymium rare earth magnets have a high resistance to demagnetization, unlike most other types of magnets. They will not lose their magnetization around other magnets or if dropped. They will however, begin to lose strength if they are heated above their maximum operating temperature, which is 176'F (80'C)

If you have never handled neodymium magnets before, you will be amazed at their strength. Neodymium magnets are over 10 x stronger than the strongest ceramic magnets. If you are currently using ceramic magnets in your project, you could probably use a much smaller neodymium magnet and have greater force.

Neodymium magnets also have some limitations due to their corrosion behaviour. In humid applications, a protective coating is highly recommended. Coatings which have been used successfully include E-coat (a liquid dip epoxy coating), dry electrostatic spray epoxy, nickel plating and combinations of these coatings. Changes in composition and processing over the past several years have resulted in significant improvements in corrosion resistance and high temperature performance.

Just like ferrite magnets neodymium magnets come in the same wide array of shapes and sizes, but because of their greatly increased size it is possible to use a measurably smaller neodymium magnet and still have an equal or greater strength than that of a ferrite magnet. This is one of the main reasons why neodymium magnets are much more widely used for healing purposes than ferrite, as a much smaller and lighter weighing magnet can be used.

The positive benefits of neodymium magnets are:

? They are the strongest magnets available approximately 10 times stronger than ferrite magnets.

? They are very lightweight.

? They do not demagnetise very easily and can with stand temperatures up to 80 C.

? They can be manufactured to a very small size e.g.2mm x 2mm and still have a strength of several thousand gauss.

The main drawback of neodymium magnets is that they have a low resistance to corrosion. To prevent corrosion from water, they must be coated with plating or an epoxy resin.

Neodymium magnets are used for all magnetic therapy healing applications. They are the first choice due to their strength and size. They will also stay magnetised for at least 10 years, so they are a very economical choice for users. Most good quality magnetic therapy jewellery, straps, wraps and bedding will contain neodymium magnets