If iron loses it's magnetism around 800 degrees C, how can the earth's core, at ~6000 degrees C, be magnetic?

Matthew Brown Matthew Brown Nov 13, 2018 · 2 mins read
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The Earth’s magnetic field is one of the most intriguing phenomena that have captured the attention of scientists for centuries. The magnetic field plays a crucial role in protecting the Earth from harmful solar winds and cosmic rays. However, the mechanism behind the Earth’s magnetic field has been a subject of debate for many years. One of the most puzzling questions is how the Earth’s core, which is composed of primarily iron and nickel, can retain its magnetism at such high temperatures.

Iron, when heated beyond a certain temperature, loses its magnetic properties. This temperature is known as the Curie temperature, which is approximately 770 degrees Celsius. Above this temperature, iron atoms lose their magnetic moment, and the material becomes non-magnetic. This phenomenon has been observed in numerous studies and is used in various applications, such as in the manufacturing of electrical devices.

However, the Earth’s core, which is estimated to be at a temperature of about 6000 degrees Celsius, still retains its magnetic properties. This has puzzled scientists for many years and is somewhat counterintuitive to what is observed in the laboratory. Scientists have proposed several theories to explain the mechanism behind the Earth’s magnetic field.

One of the most widely accepted theories proposes that the Earth’s magnetic field is generated by the dynamo effect. The dynamo effect is a process by which the convection of molten iron in the Earth’s core generates electric currents, which, in turn, create a magnetic field. This magnetic field is sustained as long as the flow of molten iron in the core continues. It is believed that the movement of molten iron in the core creates a self-sustaining system that maintains the magnetic field despite the high temperatures.

Another theory proposes that the iron in the Earth’s core is alloyed with other elements such as sulfur or oxygen. These elements may decrease the Curie temperature of iron, allowing it to retain its magnetic properties at higher temperatures. The alloying effect is observed in laboratory experiments but has not been confirmed to occur in the Earth’s core.

In conclusion, the mechanism behind the Earth’s magnetic field is still not fully understood, and scientists continue to investigate this phenomenon. Although iron loses its magnetism at around 800 degrees Celsius, the Earth’s core can retain its magnetic properties at temperatures that are much higher. The dynamo effect and the alloying effect are some of the proposed mechanisms that may explain this phenomenon. Further research is needed to fully understand the mechanism behind the Earth’s magnetic field, which plays such a critical role in the existence of life on our planet.

Matthew Brown
Written by Matthew Brown
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