Exchange coupled magnetic nanocomposites of Sm(Co1−xFex)5 / Fe3O4 with core/shell structure

Applications of exchange coupled bi-magnetic hard/soft and soft/hard magnetic core/shell nanoparticles

“…However, given the great versatility of many chemical routes in controlling materials, crystallinity, homogeneity, sizes or even shapes, less attention has been paid to the synthesis of core/shell nanoparticles using physical approaches [17][18][19][20][21][22][23][24][25][26][27][28][29][30]. Some examples of standard chemical routes used for the synthesis of hard-soft core/shell nanoparticles are coprecipitation [89][90][91], thermal decomposition [92][93][94][95][96][97][98][99][100][101][102][103][104][105][106][107][108][109], metal reduction [110,111], microwave-assisted methods [112,113] and electrodeposition [114,115].…”

“…When analyzing the magnetic properties observed experimentally for diverse hard-soft core/shell nanoparticles a spread of different behaviors can be found [91][92][93][94][95][98][99][100][102][103][104]106,107,110,111,114,115,[121][122][123][125][126][127][128][129][130][131][132]136,140,141,143,175,. First, it should be pointed out that given that we are dealing with nanoparticles the core and shell sizes are rather small (i.e., usually smaller than 2 H ), thus, most of the systems exhibit smooth hysteresis loops typical of strongly exchange coupled hard-soft counterparts.…”

Synthesis and magnetic properties of hard/soft SrFe12O19/Ni0.7Zn0.3Fe2O4 nanocomposite magnets

“…Theoretical studies have revealed that the magnetic properties of the nanocomposite permanent magnets are strongly dependent on the grain size of the hard and soft phases as well as the nature of magnetic interactions between them [9,10]. Therefore, various preparation methods such as mechanical alloying [11,12], melt spinning [13,14], gas aggregation [15] and chemical [16][17][18][19] techniques have been used to produce exchange coupled nanocomposite magnets. In hard ferrite systems as a type of the permanent magnets, applications are seriously affected by the deficiency of very low energy product.…”

Sm2Co17 nanoparticles synthesized by surfactant-assisted high energy ball milling

“…Such NPs with high magnetocrystalline anisotropy, controlled particle sizes and excellent magnetic properties have great potential for exchange coupled nanocomposites and biomedical applications. But Sm-Co nanoparticles are very active and prone to oxidation and it has been proved to be very challenging to fabricate monodisperse Sm-Co nanoparticles with high magnetic properties [1][2][3][4]. Separated Sm-Co NPs have been produced by various different techniques including mechanochemical processing, chemical synthesis, surfactant-assisted high energy ball milling [5][6][7][8].…”