The effects of Gd3+ doping on the ferromagnetic and photoluminescence properties of Co(Fe,Gd)2O4@SiO2@(Y,Gd)2O3:Eu3+ composites

• The Gd3+ doping CoFe2O4@SiO2@Y2O3:Tb3+ nanocomposites are prepared.
• Their structure, magnetic and luminescent properties are researched.
• The composites have better luminescent intensity and magnetic properties.

CoFe2O4@SiO2@(Y,Gd)2O3:Eu3+ composites were synthesized by a three-step method, following post-treatment. The composites displayed excellent ferromagnetic and photoluminescence properties. Gd3+ doping in CoFe2O4@SiO2@(Y,Gd)2O3:Eu3+ composites improved the photoluminescent intensities while decreasing the saturation magnetization. When the ratio of Y3+/Gd3+ is 0.7/0.3, the composite displayed the highest photoluminescent intensity. In the composites, the doping Gd3+ has two roles: host matrix and activator. The effects of annealing temperature on photoluminescence properties for the CoFe2O4@SiO2@(Y0.7Gd0.3)2O3:Eu3+ composites were also investigated. Meanwhile, the CoFe1.8Gd0.2O4@SiO2@Y2O3:Eu3+ composite was also prepared and the ferromagnetic and photoluminescence properties of Gd3+ doping in CoFe1.8Gd0.2O4@SiO2@Y2O3:Eu3+ composite were also investigated. The possible mechanism of the improved photoluminescent intensity of the CoFe1.8Gd0.2O4@SiO2@Y2O3:Eu3+ composite was discussed.