title: Fascinating Magnetic Energy Storage Nanomaterials: A Brief Review.
abstract: OBJECTIVE
  In this brief review, the importance of nanotechnology in developing novel magnetic energy storage materials is discussed.
  
  
  METHODS
  The discussion covers recent patents on permanent magnetic materials and especially covers processing of permanent magnets (rare-earth and rare-earth free magnets), importance of rare-earth permanent magnets and necessity of rare-earth free permanent magnets. Magnetic energy storage materials are those magnetic materials which exhibit very high energy product (BH)max (where B is the magnetic induction in Gauss (G) whereas H is the applied magnetic field in Oersted (Oe)). (BH)max is the direct measure of the ability of a magnetic material to store energy.
  
  
  RESULTS
  In this context, processing of magnetic energy storage composite materials constituted by soft and hard magnetic materials played a predominant role in achieving high (BH)max values due to the exchange coupling phenomenon between the soft and hard magnetic phases within the composite. Magnetic energy storage composites are normally composed of rare-earth magnetic materials as well as rare-earth free magnetic materials.
  
  
  CONCLUSIONS
  Nanotechnology's influence on the enhancement of energy product due to the exchange coupling phenomenon is of great prominence and therefore discussed in this review.
authors.affiliation: School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad, India.
authors.forename: Kummari V
authors.initials: KV
authors.lastname: Sreenivasulu
authors.affiliation: School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad, India.
authors.forename: Vadali V S S
authors.initials: VVSS
authors.lastname: Srikanth
keywords: Coercive field; hard magnets; magnetic energy storage; maximum energy product; nanomaterials; permanent magnets; rare earth magnets.; rare-earth free magnets