Magnetic hard/soft nanocomposite ferrite aligned hollow microfibers and remanence enhancement

Improved magnetic and electromagnetic absorption properties of xSrFe12O19/(1−x)NiFe2O4 composites

“…The magnetic hysteresis loops of the xSrFe 12 O 19 /(1−x)NiFe 2 O 4 composites display similar characteristics to those of the individual components, except for the 0.1SrFe 12 O 19 /0.9NiFe 2 O 4 and 0.3SrFe 12 O 19 /0.7NiFe 2 O 4 samples (Figure 5A), which indicates that the hard and soft magnetic phases are wellexchange-coupled 25,26. It can be seen that the magnetic hysteresis loops of the NiFe 2 O 4 and SrFe 12 O 19 ferrites demonstrate typical soft and hard magnetic characteristics, respectively (Figure5B).…”

A novel ‘one-pot’ synthetic method for preparation of (Ni0.65Zn0.35Fe2O4)x–(BaFe12O19)1−x nanocomposites and study of their microwave absorption and magnetic properties

“…According to the exchange spring theory proposed by Kneller and Hawig [23], the nanocomposite magnets consists of soft and hard phases, are known as exchange spring magnet when both the phases are sufficiently exchanged coupled with each other. The exchange spring magnets possess high saturation magnetization of soft phase and high coercivity of hard phase, which leads to produce large energy product value and are potential candidates for next generation permanent magnet [24]. These materials also exhibit improved microwave absorbing property [1,2,25,26].…”

“…In comparison to the metallic systems, the nanocomposites composed of soft spinel ferrite and hard hexagonal ferrite have shown potential to be advanced permanent magnet, because of their low cost, excellent corrosion resistance behaviour and high electrical resistivity. However, reports on soft-hard ferrite nanocomposites in the literature are very limited [1,2,24,[32][33][34][35][36][37][38] From now onwards, nanocomposites prepared by one-pot method and physical mixing method will be referred as 'composites-OP' and 'composites-PM' respectively.…”

Magnetic properties of hard-soft SrFe10Al2O19/Co0.8Ni0.2Fe2O4 ferrite synthesized by one-pot sol–gel auto-combustion

“…Efforts for improving coercivity and magnetization have resulted in the design of composite materials consisting of hard and soft magnetic phases, often collectively referred to as exchange-spring magnets [2,3]. According to the concept proposed by Kneller and Hawig [2], when both phases are sufficiently exchange coupled to each other, the high saturation magnetization of the soft phase and the high coercivity of the hard phase will be utilized for superior magnetic property of the composite compared to the individual soft and hard phase, therefore providing high magnetic energy product.…”