Coherent rotation of magnetization or Kondorsky model of exchange-decoupled BaFe10CrAlO19 dot array

BaFe10CrAlO19/Au thin films were deposited on Corning 7059 substrate by sputtering technique followed by rapid thermal annealing (RTA). The thickness of ferrite was kept constant at 50 nm. The role of annealing temperatures from 500 to 600 °C in a step of 25 °C for constant heating time of 15 min on the structural and magnetic consequences of thin films was studied. X-ray diffraction (XRD), Mössbauer spectroscopy, transmission electron microscopy, field emission scanning electron microscopy, magneto-susceptometer and vibrating sample magnetometer were used for finding the correlation between structural and magnetic properties of BaFe10CrAlO19/Au thin films. Uniaxial growth of ferrite thin films with island structure was confirmed by XRD patterns and electron microscopy evaluations. It was found that the substituted cations occupied in 12k site of BaFe10CrAlO19 structure. The maximum perpendicular coercivity of 437.69 kA/m was obtained at temperature of 575 °C. The magnetization reversal process is accompanied by coherent rotation. The magnetic interaction was mainly controlled by magnetostatic interaction. The real and imaginary parts of magnetic susceptibility display linear relation versus magnetic field.