Electric Polarization via Magnetic Ordering in the “MnBi2S4” Mineral

Context: 

A unique mechanism of electric polarization via magnetic ordering was identified in a novel mineral called “MnBi2S4.”

MnBi2S4: Electric Polarization Via Magnetic Ordering 

• The study: It is a groundbreaking discovery in the field of magnetoelectric materials 
  • It focuses on a novel material named “MnBi2S4”, which exhibits a unique mechanism of inducing electric polarization via magnetic ordering.
• Publication: The findings of the study are published in the journal PHYSICAL REVIEW B.
• Funding: Department of Science and Technology, Science and Engineering Research Board (SERB), Government of India 
• Facilities: Sheikh Saqr Laboratory and International Centre for Materials Science at Jawaharlal Nehru Centre for Advanced Scientific Research provided experimental facilities.

MnBi2S4 or Centro-symmetric

• It is also known as mineral graţianite and belongs to the ternary manganese chalcogenide family.

• The study: 

  • Tool:  High-resolution neutron diffraction was used to conduct the study, which is  crucial in characterizing the different magnetic structures responsible for electric polarization at these temperatures.
  • Findings:
    • Distinct magnetic structures were identified in the material, which includes a spin density wave (at 27 kelvin) as well as cycloidal (at 23 kelvin) and helical spin structures (at 21.5 Kelvin)
    • Most crucial discovery was the last two spin structures induced ferroelectricity in the material.
    • MnBi2S4 undergoes magnetic ordering at low temperatures (27, 23, and 21.5 Kelvins).

• Significance:

  • Breakthrough in magnetoelectric coupling: Identification of solid coupling between magnetism and electric polarization driven by magnetic frustration.
    • For the first time, it was discovered in the specific MnBi2S4 material.
  • This discovery has sparked a lot of interest in finding new materials with different types of magnetism for various applications.
  • Application:  
    • Energy-efficient data storage: It could pave the way for energy-efficient spin manipulation using small electric fields
    • It could revolutionize data storage by reducing energy consumption during writing processes.
    • Logic system: It could lead to the development of a four-state logic memory system, providing additional degrees of freedom for device performance compared to the current binary logic systems.
  • Future research: The goal is to find materials that exhibit these properties at room temperature and to understand the mechanisms that break inversion symmetry and induce polarization.

News source: PIB

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