Composite nanoparticles with variable ratios of M-type Sr-hexaferrite and maghemite phases were prepared via the sol-gel method and thermal treatment. at 600 oC. The static magnetic measurements showed variation of magnetic parameters with their relative content.
Calorimetric heating experiments on aqueous gel suspensions under in AC magnetic field (Hmax = 15.1-68.4 kAm-1, ny = 108 kHz) gave values of specific absorption rate (SAR) ranging from units to tens of W/g Fe .