Study of Y-type Hexaferrite Ba_(0.5)Sr_(1.5)ZnNiFe_(12)O_(22) Powders

摘要

We report results from a study on the influence of the substitution of Zn~(2+) cations in the Y-type Ba_(0.5)Sr_(1.5)Zn2Fe_(12)O_(22) hexaferrite, known for strong magnetoelectric coupling, with magnetic cations, such as Ni~(2+), on its structural and magnetic properties. Polycrystalline samples of Ba_(0.5)Sr_(1.5)ZnNiFe_(12)O_(22) were synthesized by citric acid sol-gel auto-combustion. The saturation magnetization value of 54.7 emu/g at 4.2 K was reduced to 37.2 emu/g at 300 K. The temperature dependence of the magnetization at magnetic fields of 50 Oe, 100 Oe and 500 Oe were used to determine the magnetic phase transition temperature. We demonstrate that the helical spin state, believed to cause the magnetoelectric effect, can be achieved by varying the magnetic field strength within a given temperature range.