Mpemba Effect in Magnets | 17 Sep 2024

Source: PIB

Recently, a study by Scientists from Jawaharlal Nehru Centre for Advanced Scientific Research, an autonomous institute of the Department of Science and Technology, has observed the Mpemba effect in magnetic materials.

  • It revealed that hotter paramagnets transition faster to their ferromagnetic phases compared to colder ones, even when they are initially at a higher temperature.
    • Paramagnets have a temporary and weaker attraction to magnetic fields due to the random alignment of atomic magnets, while ferromagnets exhibit a permanent and stronger attraction with ordered atomic magnets.
    • The transition from paramagnetic to ferromagnetic phases occurs as the temperature decreases, reaching a "critical" point known as the Curie point.
  • Mpemba Effect: It is a counterintuitive phenomenon where a hot liquid cools or freezes faster than a cooler liquid.
    • It was first noted by Aristotle in his book Meteorologica and rediscovered in the 1960s by Erasto Mpemba, a Tanzanian schoolboy.
  • Implications: It could lead to diverse applications, such as improved thermal control in devices, enhanced cooling strategies etc.

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